Evan Constable

TU Wien

*This is an algorithmically generated author record based on publicly available information.

See Latest Publications

See Most Cited Publications

SciProfiles

ORCID Profile

Google Scholar

Current Organizations / Institutes

The organizations/institutes from the scholar's latest article

TU Wien

Research Subjects

Research Interests

Evan Constable has a total of 161 co-authors. Here are the top co-authors by number of shared publications:

Roger A. Lewis
University of Wollongong
17 shared publications
Joseph Horvat
Institute for Superconducting and Electronic Materials and School of Physics, University of Wollongong, Wollongong, New South Wales 2522, Australia
6 shared publications
Sophie De Brion
Institut Néel
6 shared publications
V. Simonet
Université Grenoble Alpes, CNRS, Institut Néel, 38000 Grenoble, France
6 shared publications
Andrei Pimenov
Vienna University of Technology
5 shared publications
Claudia Decorse
ICMMO, Université Paris-Saclay, CNRS, 91400 Orsay, France
5 shared publications

Latest Publications

Sort by

Open Access
Website
Google Scholar
Cited by 13
- 15 October 2025
- Published by Springer Nature in Nature Communications
Semi-crystalline and amorphous materials via multi-temperature 3D printing from one formulation
by Michael Göschl, Dominik Laa, Thomas Koch, Evan Constable, Xin Liu, Andrei Pimenov, Jürgen Stampfl, Robert Liska, Katharina Ehrmann
Multi-material 3D printing concerns the use of two or more 3D printable materials within a single printed part. The result is a composite that benefits from the combined properties of the individual 3D printed materials. Typically, a distinct differentiation between material properties can only be achieved using multiple feedstocks and advanced engineering solutions. In this work, we create multi-material 3D printed photopolymer parts from a single monomer mixture through simple adjustments in printing temperature and light intensity. We achieve this by employing a liquid crystalline (LC) monomer that forms a highly stable LC phase in conjunction with a trifunctional thiol crosslinker. A drastic change in mechanical and optical properties was achieved depending on the presence of an LC phase during polymerization. The proof of principle from bulk experiments could be translated fully into 3D printing, achieving pixel-to-pixel resolution of the material properties solely guided by changing the printing parameters temperature and light intensity. The versatility of produced multi-material composite parts is demonstrated in shape memory applications and methods for chemical data storage and encryption.
Website
Google Scholar
- 15 October 2025
- Published by Springer Nature in Nature Communications
Open Access
Semi-crystalline and amorphous materials via multi-temperature 3D printing from one formulation
by Michael Göschl, Dominik Laa, Thomas Koch, Evan Constable, Xin Liu, Andrei Pimenov, Jürgen Stampfl, Robert Liska, Katharina Ehrmann
Multi-material 3D printing concerns the use of two or more 3D printable materials within a single printed part. The result is a composite that benefits from the combined properties of the individual 3D printed materials. Typically, a distinct differentiation between material properties can only be achieved using multiple feedstocks and advanced engineering solutions. In this work, we create multi-material 3D printed photopolymer parts from a single monomer mixture through simple adjustments in printing temperature and light intensity. We achieve this by employing a liquid crystalline (LC) monomer that forms a highly stable LC phase in conjunction with a trifunctional thiol crosslinker. A drastic change in mechanical and optical properties was achieved depending on the presence of an LC phase during polymerization. The proof of principle from bulk experiments could be translated fully into 3D printing, achieving pixel-to-pixel resolution of the material properties solely guided by changing the printing parameters temperature and light intensity. The versatility of produced multi-material composite parts is demonstrated in shape memory applications and methods for chemical data storage and encryption.
Cited by 13
Open Access
Website
Google Scholar
- 12 May 2025
- Published by American Chemical Society (ACS) in ChemRxiv
Two for one: Semi-crystalline and amorphous materials via multi-temperature 3D printing from one formulation
by Michael Göschl, Dominik Laa, Thomas Koch, Evan Constable, Andrei Pimenov, Jürgen Stampfl, Robert Liska, Katharina Ehrmann
Multi-material 3D printing concerns the use of two or more 3D printable materials within a single printed part. The result is a composite that benefits from the combined properties of the individual 3D printed materials. Typically, a distinct differentiation between material properties can only be achieved using multiple feedstocks and advanced engineering solutions. In this work, we create multi-material 3D printed photopolymer parts from a single monomer mixture through simple adjustments in printing temperature and light intensity. We achieve this by employing a liquid crystalline (LC) monomer that forms a highly stable LC phase in conjunction with a trifunctional thiol crosslinker. A drastic change in mechanical and optical properties was achieved depending on the presence of an LC phase during polymerization. The proof of principle from bulk experiments could be translated fully into 3D printing, achieving pixel-to-pixel resolution of the material properties solely guided by changing the printing parameters temperature and light intensity. The versatility of produced multi-material composite parts is demonstrated in shape memory applications and new methods for chemical data storage and encryption.
Website
Google Scholar
- 12 May 2025
- Published by American Chemical Society (ACS) in ChemRxiv
Open Access
Two for one: Semi-crystalline and amorphous materials via multi-temperature 3D printing from one formulation
by Michael Göschl, Dominik Laa, Thomas Koch, Evan Constable, Andrei Pimenov, Jürgen Stampfl, Robert Liska, Katharina Ehrmann
Multi-material 3D printing concerns the use of two or more 3D printable materials within a single printed part. The result is a composite that benefits from the combined properties of the individual 3D printed materials. Typically, a distinct differentiation between material properties can only be achieved using multiple feedstocks and advanced engineering solutions. In this work, we create multi-material 3D printed photopolymer parts from a single monomer mixture through simple adjustments in printing temperature and light intensity. We achieve this by employing a liquid crystalline (LC) monomer that forms a highly stable LC phase in conjunction with a trifunctional thiol crosslinker. A drastic change in mechanical and optical properties was achieved depending on the presence of an LC phase during polymerization. The proof of principle from bulk experiments could be translated fully into 3D printing, achieving pixel-to-pixel resolution of the material properties solely guided by changing the printing parameters temperature and light intensity. The versatility of produced multi-material composite parts is demonstrated in shape memory applications and new methods for chemical data storage and encryption.
Open Access
Website
Google Scholar
Cited by 13
- 20 September 2024
- Published by American Physical Society (APS) in PRX Energy
Semiconducting Heusler Compounds beyond the Slater-Pauling Rule
by Michael Parzer, Fabian Garmroudi, Alexander Riss, Michele Reticcioli, Raimund Podloucky, Michael Stöger-Pollach, Evan Constable, Andrej Pustogow, Takao Mori, Ernst Bauer
Heusler compounds with semiconducting properties represent an important class of functional materials. Usually, research on these systems is guided by simple electron-counting rules, such as the Slater-Pauling principle. Here, we report on the discovery of Heusler-type semiconductors, significantly deviating from the Slater-Pauling rule. We theoretically predict the occurrence of nonmagnetic semiconducting ground states in various highly off-stoichiometric full-Heusler alloys, where self-substitution leads to a band-gap opening. This unexpected trend is confirmed experimentally by thermoelectric transport measurements on a multitude of $Fe$ $_{2 - 2 x}$ $V$ $_{1 - x}$ $Al$ $_{1 + 3 x}$ samples with up to 20% substitution of $Fe$ and $V$ atoms. The band-gap opening leads to an exceptionally large Seebeck coefficient in $p$ -type $Fe$ $_{2}$ $VAl$ thermoelectrics, previously limited by bipolar conduction and low-density-of-states effective mass. Consequently, our work presents a paradigm to tune the band gap of Heusler compounds by self-substitution and introduces a hitherto unexplored class of semiconductors with exceptional thermoelectric properties, offering significant potential for advancements in energy science and sustainable-energy technologies.
Website
Google Scholar
- 20 September 2024
- Published by American Physical Society (APS) in PRX Energy
Open Access
Semiconducting Heusler Compounds beyond the Slater-Pauling Rule
by Michael Parzer, Fabian Garmroudi, Alexander Riss, Michele Reticcioli, Raimund Podloucky, Michael Stöger-Pollach, Evan Constable, Andrej Pustogow, Takao Mori, Ernst Bauer
Heusler compounds with semiconducting properties represent an important class of functional materials. Usually, research on these systems is guided by simple electron-counting rules, such as the Slater-Pauling principle. Here, we report on the discovery of Heusler-type semiconductors, significantly deviating from the Slater-Pauling rule. We theoretically predict the occurrence of nonmagnetic semiconducting ground states in various highly off-stoichiometric full-Heusler alloys, where self-substitution leads to a band-gap opening. This unexpected trend is confirmed experimentally by thermoelectric transport measurements on a multitude of $Fe$ $_{2 - 2 x}$ $V$ $_{1 - x}$ $Al$ $_{1 + 3 x}$ samples with up to 20% substitution of $Fe$ and $V$ atoms. The band-gap opening leads to an exceptionally large Seebeck coefficient in $p$ -type $Fe$ $_{2}$ $VAl$ thermoelectrics, previously limited by bipolar conduction and low-density-of-states effective mass. Consequently, our work presents a paradigm to tune the band gap of Heusler compounds by self-substitution and introduces a hitherto unexplored class of semiconductors with exceptional thermoelectric properties, offering significant potential for advancements in energy science and sustainable-energy technologies.
Cited by 13
Website
Google Scholar
Cited by 2
- 8 July 2024
- Published by American Physical Society (APS) in Physical Review B
Effect of local distortions on magnetic and magnetoelectric properties of paramagnetic $\Pr_{3} {Ga}_{5} {SiO}_{14}$ langasite
by A. Tikhanovskii, V. Yu. Ivanov, A. Kuzmenko, E. Constable, A. Pimenov, A. Mukhin
Magnetic-field-induced electric polarization has been observed in trigonal noncentrosymmetric paramagnetic $\Pr_{3} {Ga}_{5} {SiO}_{14}$ langasite. We detected quadratic electric polarization along the $a$ axis in the basal $a b$ plane for various magnetic field orientations. Electric polarization along the $c$ axis is only evident starting from the fourth power of magnetic field, in accordance with the trigonal symmetry. The magnetic properties of $\Pr_{3} {Ga}_{5} {SiO}_{14}$ primarily stem from the local anisotropic magnetic moment of the two lowest $P r^{3 +}$ singlets (quasidoublet) in the crystal electric field. The random distribution of Ga/Si in the $2 d$ positions leads to a local distortion of the $C_{2}$ symmetry and to a distribution of the quasidoublet splitting. By considering the interactions of local moments among different $P r^{3 +}$ positions within a phenomenological approach for the allowed magnetoelectric coupling, we derive the electric polarization in terms of symmetry-allowed combinations of local magnetic susceptibilities and field components. The magnetic field dependence of electric polarization in the basal plane, $P_{a, b *}$ , is mainly determined by the accumulation of effective local susceptibilities, exhibiting similar behavior in low fields, while polarization along the $c$ axis, $P_{c}$ , arises from the nonequivalence of local effective magnetic susceptibilities in different $P r^{3 +}$ positions. Our findings suggest that the temperature dependencies of magnetic and magnetoelectric susceptibilities are highly sensitive to the distribution of the quasidoublet splitting, which reflects the local symmetry breaking.
Website
Google Scholar
- 8 July 2024
- Published by American Physical Society (APS) in Physical Review B
Effect of local distortions on magnetic and magnetoelectric properties of paramagnetic $\Pr_{3} {Ga}_{5} {SiO}_{14}$ langasite
by A. Tikhanovskii, V. Yu. Ivanov, A. Kuzmenko, E. Constable, A. Pimenov, A. Mukhin
Magnetic-field-induced electric polarization has been observed in trigonal noncentrosymmetric paramagnetic $\Pr_{3} {Ga}_{5} {SiO}_{14}$ langasite. We detected quadratic electric polarization along the $a$ axis in the basal $a b$ plane for various magnetic field orientations. Electric polarization along the $c$ axis is only evident starting from the fourth power of magnetic field, in accordance with the trigonal symmetry. The magnetic properties of $\Pr_{3} {Ga}_{5} {SiO}_{14}$ primarily stem from the local anisotropic magnetic moment of the two lowest $P r^{3 +}$ singlets (quasidoublet) in the crystal electric field. The random distribution of Ga/Si in the $2 d$ positions leads to a local distortion of the $C_{2}$ symmetry and to a distribution of the quasidoublet splitting. By considering the interactions of local moments among different $P r^{3 +}$ positions within a phenomenological approach for the allowed magnetoelectric coupling, we derive the electric polarization in terms of symmetry-allowed combinations of local magnetic susceptibilities and field components. The magnetic field dependence of electric polarization in the basal plane, $P_{a, b *}$ , is mainly determined by the accumulation of effective local susceptibilities, exhibiting similar behavior in low fields, while polarization along the $c$ axis, $P_{c}$ , arises from the nonequivalence of local effective magnetic susceptibilities in different $P r^{3 +}$ positions. Our findings suggest that the temperature dependencies of magnetic and magnetoelectric susceptibilities are highly sensitive to the distribution of the quasidoublet splitting, which reflects the local symmetry breaking.
Cited by 2
Website
Google Scholar
Cited by 1
- 21 June 2024
- Published by American Physical Society (APS) in Physical Review B
Resolving the local distortions of Ising-like moments in magnetoelectric Ho-doped langasite
by A. Yu. Tikhanovskii, V. Yu. Ivanov, A. M. Kuzmenko, A. Stunault, O. Fabelo, E. Ressouche, V. Simonet, R. Ballou, I. A. Kibalin, A. Pimenov, et al.
The magnetic properties of Ho-doped langasites ${(La : Ho)}_{3} G a_{5} Si O_{14}$ are dominated by the Ising-like magnetic moments of the $H o^{3 +}$ ions. In their saturated regime, the induced magnetic state breaks both time and space inversion symmetries, leading to a linear magnetoelectric effect. However, due to distortions induced by a shared Ga/Si occupancy of the $2 d$ sites, resolving the microscopic nature of the magnetic configuration remains a difficult task. Here, we combine polarized neutron diffraction and angular-dependent magnetization experiments to determine the local distortions of the $H o^{3 +}$ magnetic moments in doped langasites ${(L a_{1 - x} H o_{x})}_{3} G a_{5} Si O_{14}$ with $x \approx 0.015$ and 0.045. We propose a model for a field-induced magnetic configuration with arbitrary orientations of the local Ising axis of $H o^{3 +}$ in distorted positions. The operations of broken local $C_{2}$ symmetry and rotations around the trigonal $C_{3}$ axis connect different sites, restoring the global $P 321$ symmetry of the crystal and simplifying the description of the magnetic properties. The superposition of two distorted $H o^{3 +}$ positions connected by $C_{2}$ symmetry determines the local magnetic susceptibility tensor, which no longer appears Ising-like at low fields.
Website
Google Scholar
- 21 June 2024
- Published by American Physical Society (APS) in Physical Review B
Resolving the local distortions of Ising-like moments in magnetoelectric Ho-doped langasite
by A. Yu. Tikhanovskii, V. Yu. Ivanov, A. M. Kuzmenko, A. Stunault, O. Fabelo, E. Ressouche, V. Simonet, R. Ballou, I. A. Kibalin, A. Pimenov, et al.
The magnetic properties of Ho-doped langasites ${(La : Ho)}_{3} G a_{5} Si O_{14}$ are dominated by the Ising-like magnetic moments of the $H o^{3 +}$ ions. In their saturated regime, the induced magnetic state breaks both time and space inversion symmetries, leading to a linear magnetoelectric effect. However, due to distortions induced by a shared Ga/Si occupancy of the $2 d$ sites, resolving the microscopic nature of the magnetic configuration remains a difficult task. Here, we combine polarized neutron diffraction and angular-dependent magnetization experiments to determine the local distortions of the $H o^{3 +}$ magnetic moments in doped langasites ${(L a_{1 - x} H o_{x})}_{3} G a_{5} Si O_{14}$ with $x \approx 0.015$ and 0.045. We propose a model for a field-induced magnetic configuration with arbitrary orientations of the local Ising axis of $H o^{3 +}$ in distorted positions. The operations of broken local $C_{2}$ symmetry and rotations around the trigonal $C_{3}$ axis connect different sites, restoring the global $P 321$ symmetry of the crystal and simplifying the description of the magnetic properties. The superposition of two distorted $H o^{3 +}$ positions connected by $C_{2}$ symmetry determines the local magnetic susceptibility tensor, which no longer appears Ising-like at low fields.
Cited by 1
Open Access
Website
Google Scholar
Cited by 2
- 6 March 2024
- Published by Springer Nature in Scientific Reports
Encoding terahertz holographic bits with a computer-generated 3D-printed phase plate
by E. Constable, J. Gospodaric, A. Pimenov
A sub-terahertz holographic image of a two-dimensional 576-bit data code is produced using a diffractive phase-plate element. The phase plate was designed using a modified Gerchberg-Saxton iterative algorithm to encode a focused image of the data code into a phase modulation profile. The complex phase plate structure is fabricated from polylactic acid using fused deposition modeling, a common three-dimensional-printing technique. The design achieves a significantly simplified optical setup, consisting of a 0.14 THz diverging source, the holographic phase plate and a scanning detector, without the need for additional optical elements. The information stored in the data code is an example of a cryptographic private key. Specifically, the private key for a Bitcoin wallet address. Successful retrieval of the encoded information demonstrates a potential use case for terahertz holographic memory, using a storage medium that can be fabricated with consumer-level three-dimensional-printing techniques.
Website
Google Scholar
- 6 March 2024
- Published by Springer Nature in Scientific Reports
Open Access
Encoding terahertz holographic bits with a computer-generated 3D-printed phase plate
by E. Constable, J. Gospodaric, A. Pimenov
A sub-terahertz holographic image of a two-dimensional 576-bit data code is produced using a diffractive phase-plate element. The phase plate was designed using a modified Gerchberg-Saxton iterative algorithm to encode a focused image of the data code into a phase modulation profile. The complex phase plate structure is fabricated from polylactic acid using fused deposition modeling, a common three-dimensional-printing technique. The design achieves a significantly simplified optical setup, consisting of a 0.14 THz diverging source, the holographic phase plate and a scanning detector, without the need for additional optical elements. The information stored in the data code is an example of a cryptographic private key. Specifically, the private key for a Bitcoin wallet address. Successful retrieval of the encoded information demonstrates a potential use case for terahertz holographic memory, using a storage medium that can be fabricated with consumer-level three-dimensional-printing techniques.
Cited by 2
Open Access
Website
Google Scholar
- 9 November 2023
- Published by Springer Nature in Research Square
Terahertz holographic data storage with a 3D printed phase plate
by Evan Constable, Jan Gospodaric, Andrei Pimenov
A sub-terahertz holographic image of a two-dimensional 576-bit data code is produced using a diffractive phase-plate element. The phase plate was designed using a modified Gerchberg-Saxton iterative algorithm to encode a focused image of the data code into a phase modulation profile. The complex phase plate structure is fabricated from polylactic acid using fused deposition modeling, a common three-dimensional-printing technique. The design allows for a significantly simplified optical setup, consisting of a 0.14 THz diverging source, the holographic phase plate and a scanning detector, in co-linear alignment. The information stored in the data code is an example of a cryptography private key. Specifically, the private key for a Bitcoin wallet address. Convincing detection of the encoded information demonstrates a practical use case for terahertz holographic data storage, using a storage medium that can be fabricated with consumer-level three-dimensional-printing techniques.
Website
Google Scholar
- 9 November 2023
- Published by Springer Nature in Research Square
Open Access
Terahertz holographic data storage with a 3D printed phase plate
by Evan Constable, Jan Gospodaric, Andrei Pimenov
A sub-terahertz holographic image of a two-dimensional 576-bit data code is produced using a diffractive phase-plate element. The phase plate was designed using a modified Gerchberg-Saxton iterative algorithm to encode a focused image of the data code into a phase modulation profile. The complex phase plate structure is fabricated from polylactic acid using fused deposition modeling, a common three-dimensional-printing technique. The design allows for a significantly simplified optical setup, consisting of a 0.14 THz diverging source, the holographic phase plate and a scanning detector, in co-linear alignment. The information stored in the data code is an example of a cryptography private key. Specifically, the private key for a Bitcoin wallet address. Convincing detection of the encoded information demonstrates a practical use case for terahertz holographic data storage, using a storage medium that can be fabricated with consumer-level three-dimensional-printing techniques.
Website
Google Scholar
Cited by 11
- 8 June 2023
- Published by American Physical Society (APS) in Physical Review B
Vibronic collapse of ordered quadrupolar ice in the pyrochlore magnet ${Tb}_{2 + x} {Ti}_{2 - x} O_{7 + y}$
by Y. Alexanian, J. Robert, V. Simonet, B. Langérôme, J.-B. Brubach, P. Roy, C. Decorse, E. Lhotel, E. Constable, R. Ballou, et al.
While the spin-liquid state in the frustrated pyrochlore ${Tb}_{2 + x} {Ti}_{2 - x} O_{7 + y}$ has been studied both experimentally and theoretically for more than two decades, a definite description of this unconventional state still needs to be achieved. Using synchrotron-based THz spectroscopy in combination with quantum numerical simulations, we highlight a significant link between two features: the existence of a quadrupolar order following an ice rule and the presence of strong magnetoelastic coupling in the form of hybridized ${Tb}^{3 +}$ crystal-field and phonon modes. The magnitude of this so-called vibronic process, which involves quadrupolar degrees of freedom, is significantly dependent on small off-stoichiometry $x$ and favors all-in–all-out-like correlations between quadrupoles. This mechanism competes with the long-range ordered quadrupolar ice, and for slightly different stoichiometry, is able to destabilize it.
Website
Google Scholar
- 8 June 2023
- Published by American Physical Society (APS) in Physical Review B
Vibronic collapse of ordered quadrupolar ice in the pyrochlore magnet ${Tb}_{2 + x} {Ti}_{2 - x} O_{7 + y}$
by Y. Alexanian, J. Robert, V. Simonet, B. Langérôme, J.-B. Brubach, P. Roy, C. Decorse, E. Lhotel, E. Constable, R. Ballou, et al.
While the spin-liquid state in the frustrated pyrochlore ${Tb}_{2 + x} {Ti}_{2 - x} O_{7 + y}$ has been studied both experimentally and theoretically for more than two decades, a definite description of this unconventional state still needs to be achieved. Using synchrotron-based THz spectroscopy in combination with quantum numerical simulations, we highlight a significant link between two features: the existence of a quadrupolar order following an ice rule and the presence of strong magnetoelastic coupling in the form of hybridized ${Tb}^{3 +}$ crystal-field and phonon modes. The magnitude of this so-called vibronic process, which involves quadrupolar degrees of freedom, is significantly dependent on small off-stoichiometry $x$ and favors all-in–all-out-like correlations between quadrupoles. This mechanism competes with the long-range ordered quadrupolar ice, and for slightly different stoichiometry, is able to destabilize it.
Cited by 11
Open Access
Website
Google Scholar
- 16 March 2023
- Published by American Physical Society (APS) in Physical Review Research
Spectroscopic signature of sublattice polarization in the lattice dynamics of an antiferroelectric crystal
by E. Constable, L. Bergen, A. Shuvaev, J. Wettstein, L. Weymann, E. Malysheva, A. Pimenov, M. Guennou
Spectroscopic measurements of the far-infrared phonon dynamics for a model antiferroelectric crystal are performed at low temperature. In agreement with the phenomenological expectations for a displacive antiferroelectric transition, a polar soft mode associated to a close-lying polar phase of the otherwise centrosymmetric structure is observed. Incomplete softening of the polar soft mode due to the antiferroelectric transition quantifies the energy barrier between the neighboring states. The dynamics are modeled with a biquadratic Landau potential incorporating a symmetry constraining effective interaction between displaced ions. A signature of sublattice polarization is observed in a scaling of the effective antipolar interaction in the antiferroelectric phase.
Website
Google Scholar
- 16 March 2023
- Published by American Physical Society (APS) in Physical Review Research
Open Access
Spectroscopic signature of sublattice polarization in the lattice dynamics of an antiferroelectric crystal
by E. Constable, L. Bergen, A. Shuvaev, J. Wettstein, L. Weymann, E. Malysheva, A. Pimenov, M. Guennou
Spectroscopic measurements of the far-infrared phonon dynamics for a model antiferroelectric crystal are performed at low temperature. In agreement with the phenomenological expectations for a displacive antiferroelectric transition, a polar soft mode associated to a close-lying polar phase of the otherwise centrosymmetric structure is observed. Incomplete softening of the polar soft mode due to the antiferroelectric transition quantifies the energy barrier between the neighboring states. The dynamics are modeled with a biquadratic Landau potential incorporating a symmetry constraining effective interaction between displaced ions. A signature of sublattice polarization is observed in a scaling of the effective antipolar interaction in the antiferroelectric phase.
Open Access
Website
Google Scholar
Cited by 4
- 30 July 2021
- Published by American Physical Society (APS) in Physical Review B
Lattice contributions to the anisotropic dielectric response of rare-earth langasites
by L. Bergen, L. Weymann, J. Wettstein, A. M. Kuzmenko, A. A. Mukhin, B. V. Mill, A. Pimenov, E. Constable
We investigate the phonon spectrum of pure and rare-earth substituted langasites. For electric fields oriented along the $c$ axis, a strong low-frequency phonon is observed, softening at lower temperature in all samples studied. The dielectric contribution and temperature dependence of this mode is the primary source of the large $[ɛ (0) \sim 100]$ static dielectric permittivity observed in these systems. Softening of this mode with increasing mass of the rare-earth substitutes further suggests that langasites are close to a structural instability at low temperatures. The application of a magnetic field to a diluted Ho-langasite sample reveals a shift in the strong absorption band at THz frequencies associated with this soft lattice mode, suggesting spin-lattice effects may also be at play in these systems.
Website
Google Scholar
- 30 July 2021
- Published by American Physical Society (APS) in Physical Review B
Open Access
Lattice contributions to the anisotropic dielectric response of rare-earth langasites
by L. Bergen, L. Weymann, J. Wettstein, A. M. Kuzmenko, A. A. Mukhin, B. V. Mill, A. Pimenov, E. Constable
We investigate the phonon spectrum of pure and rare-earth substituted langasites. For electric fields oriented along the $c$ axis, a strong low-frequency phonon is observed, softening at lower temperature in all samples studied. The dielectric contribution and temperature dependence of this mode is the primary source of the large $[ɛ (0) \sim 100]$ static dielectric permittivity observed in these systems. Softening of this mode with increasing mass of the rare-earth substitutes further suggests that langasites are close to a structural instability at low temperatures. The application of a magnetic field to a diluted Ho-langasite sample reveals a shift in the strong absorption band at THz frequencies associated with this soft lattice mode, suggesting spin-lattice effects may also be at play in these systems.
Cited by 4

Show all