Keith A. McEwen

UCL Australia

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Keith A. McEwen has a total of 423 co-authors. Here are the top co-authors by number of shared publications:

J.-G. Park
Department of Physics and Institute of Basic Science, Sungkyunkwan University, Suwon 440-746, Korea
22 shared publications
D. Fort
Department of Metallurgy and Materials Science, University of Birmingham, Birmingham B15 2TT, United Kingdom
17 shared publications
E. Colineau
14 shared publications
Helen Claire Walker
ISIS Pulsed Neutron and Muon Source STFC Rutherford Appleton Laboratory Harwell Campus Didcot OX11 0QX UK
13 shared publications
Jens Jensen
Niels Bohr Institute
12 shared publications
M. Ellerby
University College London
11 shared publications

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Cited by 11
- 15 June 2018
- Published by Physical Society of Japan in Journal of the Physical Society of Japan
Zero-Field Ambient-Pressure Quantum Criticality in the Stoichiometric Non-Fermi Liquid System CeRhBi
by Vivek K. Anand, Devashibhai T. Adroja, Adrian D. Hillier, Keisuke Shigetoh, Toshiro Takabatake, Je-Geun Park, Keith A. McEwen, Jedediah H. Pixley, Qimiao Si
We present the spin dynamics study of a stoichiometric non-Fermi liquid (NFL) system CeRhBi, using low-energy inelastic neutron scattering (INS) and muon spin relaxation (μSR) measurements. It shows evidence for an energy-temperature (E/T) scaling in the INS dynamic response and a time-field (t/H^η) scaling of the μSR asymmetry function indicating a quantum critical behavior in this compound. The E/T scaling reveals a local character of quantum criticality consistent with the power-law divergence of the magnetic susceptibility, logarithmic divergence of the magnetic heat capacity and T-linear resistivity at low temperature. The occurrence of NFL behavior and local criticality over a very wide dynamical range at zero field and ambient pressure without any tuning in this stoichiometric heavy fermion compound is striking, making CeRhBi a model system amenable to in-depth studies for quantum criticality.
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- 15 June 2018
- Published by Physical Society of Japan in Journal of the Physical Society of Japan
Zero-Field Ambient-Pressure Quantum Criticality in the Stoichiometric Non-Fermi Liquid System CeRhBi
by Vivek K. Anand, Devashibhai T. Adroja, Adrian D. Hillier, Keisuke Shigetoh, Toshiro Takabatake, Je-Geun Park, Keith A. McEwen, Jedediah H. Pixley, Qimiao Si
We present the spin dynamics study of a stoichiometric non-Fermi liquid (NFL) system CeRhBi, using low-energy inelastic neutron scattering (INS) and muon spin relaxation (μSR) measurements. It shows evidence for an energy-temperature (E/T) scaling in the INS dynamic response and a time-field (t/H^η) scaling of the μSR asymmetry function indicating a quantum critical behavior in this compound. The E/T scaling reveals a local character of quantum criticality consistent with the power-law divergence of the magnetic susceptibility, logarithmic divergence of the magnetic heat capacity and T-linear resistivity at low temperature. The occurrence of NFL behavior and local criticality over a very wide dynamical range at zero field and ambient pressure without any tuning in this stoichiometric heavy fermion compound is striking, making CeRhBi a model system amenable to in-depth studies for quantum criticality.
Cited by 11
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Cited by 14
- 10 October 2016
- Published by Trans Tech Publications, Ltd. in Solid State Phenomena
Inelastic Neutron Scattering Investigations of an Anisotropic Hybridization Gap in the Kondo Insulators: CeT2Al10 (T=Fe, Ru and Os)
by Devashibhai T. Adroja, Y. Muro, Toshiro Takabatake, Le, H.C. Walker, K.A. McEwen, Andrew T. Boothroyd
The recent discovery of topological Kondo insulating behaviour in strongly correlated electron systems has generated considerable interest in Kondo insulators both experimentally and theoretically. The Kondo semiconductors CeT₂Al₁₀ (T=Fe, Ru and Os) possessing a c-f hybridization gap have received considerable attention recently because of the unexpected high magnetic ordering temperature of CeRu₂Al₁₀ (T_N=27 K) and CeOs₂Al₁₀ (T_N=28.5 K) and the Kondo insulating behaviour observed in the valence fluctuating compound CeFe₂Al₁₀ with a paramagnetic ground state down to 50 mK. We are investigating this family of compounds, both in polycrystalline and single crystal form, using inelastic neutron scattering to understand the role of anisotropic c-f hybridization on the spin gap formation as well as on their magnetic properties. We have observed a clear sign of a spin gap in all three compounds from our polycrystalline study as well as the existence of a spin gap above the magnetic ordering temperature in T=Ru and Os. Our inelastic neutron scattering studies on single crystals of CeRu₂Al₁₀ and CeOs₂Al₁₀ revealed dispersive gapped spin wave excitations below T_N. Analysis of the spin wave spectrum reveals the presence of strong anisotropic exchange, along the c-axis (or z-axis) stronger than in the ab-plane. These anisotropic exchange interactions force the magnetic moment to align along the c-axis, competing with the single ion crystal field anisotropy, which prefers moments along the a-axis. In the paramagnetic state (below 50 K) of the Kondo insulator CeFe₂Al₁₀, we have also observed dispersive gapped magnetic excitations which transform into quasi-elastic scattering on heating to 100 K. We will discuss the origin of the anisotropic hybridization gap in CeFe₂Al₁₀ based on theoretical models of heavy-fermion semiconductors.
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- 10 October 2016
- Published by Trans Tech Publications, Ltd. in Solid State Phenomena
Inelastic Neutron Scattering Investigations of an Anisotropic Hybridization Gap in the Kondo Insulators: CeT2Al10 (T=Fe, Ru and Os)
by Devashibhai T. Adroja, Y. Muro, Toshiro Takabatake, Le, H.C. Walker, K.A. McEwen, Andrew T. Boothroyd
The recent discovery of topological Kondo insulating behaviour in strongly correlated electron systems has generated considerable interest in Kondo insulators both experimentally and theoretically. The Kondo semiconductors CeT₂Al₁₀ (T=Fe, Ru and Os) possessing a c-f hybridization gap have received considerable attention recently because of the unexpected high magnetic ordering temperature of CeRu₂Al₁₀ (T_N=27 K) and CeOs₂Al₁₀ (T_N=28.5 K) and the Kondo insulating behaviour observed in the valence fluctuating compound CeFe₂Al₁₀ with a paramagnetic ground state down to 50 mK. We are investigating this family of compounds, both in polycrystalline and single crystal form, using inelastic neutron scattering to understand the role of anisotropic c-f hybridization on the spin gap formation as well as on their magnetic properties. We have observed a clear sign of a spin gap in all three compounds from our polycrystalline study as well as the existence of a spin gap above the magnetic ordering temperature in T=Ru and Os. Our inelastic neutron scattering studies on single crystals of CeRu₂Al₁₀ and CeOs₂Al₁₀ revealed dispersive gapped spin wave excitations below T_N. Analysis of the spin wave spectrum reveals the presence of strong anisotropic exchange, along the c-axis (or z-axis) stronger than in the ab-plane. These anisotropic exchange interactions force the magnetic moment to align along the c-axis, competing with the single ion crystal field anisotropy, which prefers moments along the a-axis. In the paramagnetic state (below 50 K) of the Kondo insulator CeFe₂Al₁₀, we have also observed dispersive gapped magnetic excitations which transform into quasi-elastic scattering on heating to 100 K. We will discuss the origin of the anisotropic hybridization gap in CeFe₂Al₁₀ based on theoretical models of heavy-fermion semiconductors.
Cited by 14
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Cited by 2
- 27 May 2015
- Published by American Physical Society (APS) in Physical Review B
Magnetic, electrical, and thermodynamic properties of NpIr: Ambient and high-pressure measurements, and electronic structure calculations
by H. C. Walker, K. A. McEwen, J.-C. Griveau, R. Eloirdi, P. Amador, P. Maldonado, P. M. Oppeneer, E. Colineau
We present bulk property measurements of NpIr, a newly synthesized member of the Np-Ir binary phase diagram, which is isostructural to the noncentrosymmetric pressure-induced ferromagnetic superconductor UIr. Magnetic susceptibility, electronic transport properties at ambient and high pressure, and heat capacity measurements have been performed for temperatures $T = 0.55 – 300$ K in a range of magnetic fields up to 14 T and under pressure up to $17.3$ GPa. These reveal that NpIr is a moderately heavy fermion Kondo system with strong antiferromagnetic interactions, but there is no evidence of any phase transition down to $0.55$ K or at the highest pressure achieved. Experimental results are compared with ab initio calculations of the electronic band structure and lattice heat capacity. An extremely low lattice thermal conductivity is predicted for NpIr at temperatures above 300 K.
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- 27 May 2015
- Published by American Physical Society (APS) in Physical Review B
Open Access
Magnetic, electrical, and thermodynamic properties of NpIr: Ambient and high-pressure measurements, and electronic structure calculations
by H. C. Walker, K. A. McEwen, J.-C. Griveau, R. Eloirdi, P. Amador, P. Maldonado, P. M. Oppeneer, E. Colineau
We present bulk property measurements of NpIr, a newly synthesized member of the Np-Ir binary phase diagram, which is isostructural to the noncentrosymmetric pressure-induced ferromagnetic superconductor UIr. Magnetic susceptibility, electronic transport properties at ambient and high pressure, and heat capacity measurements have been performed for temperatures $T = 0.55 – 300$ K in a range of magnetic fields up to 14 T and under pressure up to $17.3$ GPa. These reveal that NpIr is a moderately heavy fermion Kondo system with strong antiferromagnetic interactions, but there is no evidence of any phase transition down to $0.55$ K or at the highest pressure achieved. Experimental results are compared with ab initio calculations of the electronic band structure and lattice heat capacity. An extremely low lattice thermal conductivity is predicted for NpIr at temperatures above 300 K.
Cited by 2
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Cited by 69
- 23 July 2014
- Published by American Physical Society (APS) in Physical Review B
Physical properties of noncentrosymmetric superconductor ${LaIrSi}_{3}$ : A $μ$ SR study
by V. K. Anand, D. Britz, A. Bhattacharyya, D. T. Adroja, A. D. Hillier, A. M. Strydom, W. Kockelmann, B. D. Rainford, K. A. McEwen
The results of heat capacity $C_{p} (T, H)$ and electrical resistivity $ρ (T, H)$ measurements down to 0.35 K as well as muon spin relaxation and rotation $(μ SR)$ measurements on the noncentrosymmetric superconductor ${LaIrSi}_{3}$ are presented. Powder neutron diffraction confirmed the reported noncentrosymmetric body-centered tetragonal ${BaNiSn}_{3}$ -type structure (space group $I 4 m m)$ of ${LaIrSi}_{3}$ . The bulk superconductivity is observed below $T_{c} = 0.72 (1)$ K. The intrinsic $Δ C_{e} / γ_{n} T_{c} = 1.09 (3)$ is significantly smaller than the BCS value of 1.43, and this reduction is accounted for by the $α$ model of BCS superconductivity. The analysis of the superconducting-state $C_{e} (T)$ data by the single-band $α$ model indicates a moderately anisotropic order parameter with the $s$ -wave gap $Δ (0) / k_{B} T_{c} = 1.54 (2)$ , which is lower than the BCS value of 1.764. Our estimates of various normal- and superconducting-state parameters indicate a weakly coupled electron-phonon-driven type-I $s$ -wave superconductivity in ${LaIrSi}_{3}$ . The $μ$ SR results also confirm the conventional type-I superconductivity in ${LaIrSi}_{3}$ with a preserved time-reversal symmetry and hence a singlet pairing superconducting ground state.
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- 23 July 2014
- Published by American Physical Society (APS) in Physical Review B
Physical properties of noncentrosymmetric superconductor ${LaIrSi}_{3}$ : A $μ$ SR study
by V. K. Anand, D. Britz, A. Bhattacharyya, D. T. Adroja, A. D. Hillier, A. M. Strydom, W. Kockelmann, B. D. Rainford, K. A. McEwen
The results of heat capacity $C_{p} (T, H)$ and electrical resistivity $ρ (T, H)$ measurements down to 0.35 K as well as muon spin relaxation and rotation $(μ SR)$ measurements on the noncentrosymmetric superconductor ${LaIrSi}_{3}$ are presented. Powder neutron diffraction confirmed the reported noncentrosymmetric body-centered tetragonal ${BaNiSn}_{3}$ -type structure (space group $I 4 m m)$ of ${LaIrSi}_{3}$ . The bulk superconductivity is observed below $T_{c} = 0.72 (1)$ K. The intrinsic $Δ C_{e} / γ_{n} T_{c} = 1.09 (3)$ is significantly smaller than the BCS value of 1.43, and this reduction is accounted for by the $α$ model of BCS superconductivity. The analysis of the superconducting-state $C_{e} (T)$ data by the single-band $α$ model indicates a moderately anisotropic order parameter with the $s$ -wave gap $Δ (0) / k_{B} T_{c} = 1.54 (2)$ , which is lower than the BCS value of 1.764. Our estimates of various normal- and superconducting-state parameters indicate a weakly coupled electron-phonon-driven type-I $s$ -wave superconductivity in ${LaIrSi}_{3}$ . The $μ$ SR results also confirm the conventional type-I superconductivity in ${LaIrSi}_{3}$ with a preserved time-reversal symmetry and hence a singlet pairing superconducting ground state.
Cited by 69
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Cited by 4
- 10 June 2014
- Published by American Physical Society (APS) in Physical Review B
Mean-field model for the quadrupolar phases of ${UPd}_{3}$
by Manh Duc Le, Keith A. McEwen, Martin Rotter, Mathias Doerr, Alexander Barcza, Je-Geun Park, James Brooks, Eric Jobiliong, David Fort
${UPd}_{3}$ is known to exhibit four antiferroquadrupolar ordered phases at low temperatures. We report measur-ements of the magnetization and magnetostriction of single crystal ${UPd}_{3}$ , along the principal symmetry directions, in fields up to 33 T. These results have been combined with recent inelastic neutron and x-ray resonant scattering measurements to construct a mean-field model of ${UPd}_{3}$ including up to fourth nearest-neighbor interactions. In particular, we find that anisotropic quadrupolar interactions must be included in order to explain the low-temperature structures derived from the scattering data.
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- 10 June 2014
- Published by American Physical Society (APS) in Physical Review B
Mean-field model for the quadrupolar phases of ${UPd}_{3}$
by Manh Duc Le, Keith A. McEwen, Martin Rotter, Mathias Doerr, Alexander Barcza, Je-Geun Park, James Brooks, Eric Jobiliong, David Fort
${UPd}_{3}$ is known to exhibit four antiferroquadrupolar ordered phases at low temperatures. We report measur-ements of the magnetization and magnetostriction of single crystal ${UPd}_{3}$ , along the principal symmetry directions, in fields up to 33 T. These results have been combined with recent inelastic neutron and x-ray resonant scattering measurements to construct a mean-field model of ${UPd}_{3}$ including up to fourth nearest-neighbor interactions. In particular, we find that anisotropic quadrupolar interactions must be included in order to explain the low-temperature structures derived from the scattering data.
Cited by 4
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Cited by 27
- 18 October 2013
- Published by IOP Publishing in Journal of Physics: Condensed Matter
Large in-plane deformation of RuO₆octahedron and ferromagnetism of bulk SrRuO₃
by Sanghyun Lee, J R Zhang, S Torii, Seongil Choi, Deok-Yong Cho, T Kamiyama, Jaejun Yu, K A McEwen, Je-Geun Park
SrRuO3 is a ferromagnetic metal with several unusual physical properties such as zero thermal expansion below Tc, so-called Invar behavior. Another anomalous feature is that the a-axis lattice constant is larger than the b-axis lattice constant, a clear deviation from the predictions of the Glazer structural description with rigid RuO6 octahedron motion. Using high resolution neutron diffraction techniques, we show how these two structural anomalies arise from the irregular in-plane deformation, i.e. plastic behavior of the RuO6 octahedron, a weak band Jahn-Teller distortion. We further demonstrate that the ferromagnetic instability of SrRuO3 is related to the temperature-induced localization of Ru 4d bands.
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- 18 October 2013
- Published by IOP Publishing in Journal of Physics: Condensed Matter
Large in-plane deformation of RuO₆octahedron and ferromagnetism of bulk SrRuO₃
by Sanghyun Lee, J R Zhang, S Torii, Seongil Choi, Deok-Yong Cho, T Kamiyama, Jaejun Yu, K A McEwen, Je-Geun Park
SrRuO3 is a ferromagnetic metal with several unusual physical properties such as zero thermal expansion below Tc, so-called Invar behavior. Another anomalous feature is that the a-axis lattice constant is larger than the b-axis lattice constant, a clear deviation from the predictions of the Glazer structural description with rigid RuO6 octahedron motion. Using high resolution neutron diffraction techniques, we show how these two structural anomalies arise from the irregular in-plane deformation, i.e. plastic behavior of the RuO6 octahedron, a weak band Jahn-Teller distortion. We further demonstrate that the ferromagnetic instability of SrRuO3 is related to the temperature-induced localization of Ru 4d bands.
Cited by 27
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- 11 October 2013
- Published by Taylor & Francis in Neutron News
The International Conference on Neutron Scattering 2013 in Edinburgh
by Inês Crespo, Keith McEwen
(2013). The International Conference on Neutron Scattering 2013 in Edinburgh. Neutron News: Vol. 24, No. 4, pp. 4-6.
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- 11 October 2013
- Published by Taylor & Francis in Neutron News
Open Access
The International Conference on Neutron Scattering 2013 in Edinburgh
by Inês Crespo, Keith McEwen
(2013). The International Conference on Neutron Scattering 2013 in Edinburgh. Neutron News: Vol. 24, No. 4, pp. 4-6.
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Cited by 22
- 24 June 2013
- Published by American Physical Society (APS) in Physical Review B
Field-induced long-range magnetic order in the spin-singlet ground-state system YbAl $_{3}$ C $_{3}$ : Neutron diffraction study
by D. D. Khalyavin, D. T. Adroja, P. Manuel, A. Daoud-Aladine, M. Kosaka, K. Kondo, K. A. McEwen, J. H. Pixley, Qimiao Si
The $4 f$ -electron system YbAl $_{3}$ C $_{3}$ with a nonmagnetic spin-dimer ground state has been studied by neutron diffraction in an applied magnetic field. A long-range magnetic order involving both ferromagnetic and antiferromagnetic components has been revealed above the critical field $H_{C} \sim 6$ T at temperature $T = 0.05$ K. The magnetic structure indicates that the geometrical frustration of the prototype hexagonal lattice is not fully relieved in the low-temperature orthorhombic phase. The suppression of magnetic ordering by the remanent frustration is the key factor stabilizing the nonmagnetic singlet ground state in zero field. Temperature-dependent measurements in the applied field $H = 12$ T revealed that the long-range ordering persists up to temperatures significantly higher than the spin gap, indicating that this phase is not directly related to the singlet-triplet excitation. Combining our neutron diffraction results with the previously published phase diagram, we support the existence of an intermediate disordered phase as the first excitation from the nonmagnetic singlet ground state. Based on our results, we propose YbAl $_{3}$ C $_{3}$ as a material for studying the quantum phase transitions of heavy-fermion metals under the influence of geometrical frustration.
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- 24 June 2013
- Published by American Physical Society (APS) in Physical Review B
Open Access
Field-induced long-range magnetic order in the spin-singlet ground-state system YbAl $_{3}$ C $_{3}$ : Neutron diffraction study
by D. D. Khalyavin, D. T. Adroja, P. Manuel, A. Daoud-Aladine, M. Kosaka, K. Kondo, K. A. McEwen, J. H. Pixley, Qimiao Si
The $4 f$ -electron system YbAl $_{3}$ C $_{3}$ with a nonmagnetic spin-dimer ground state has been studied by neutron diffraction in an applied magnetic field. A long-range magnetic order involving both ferromagnetic and antiferromagnetic components has been revealed above the critical field $H_{C} \sim 6$ T at temperature $T = 0.05$ K. The magnetic structure indicates that the geometrical frustration of the prototype hexagonal lattice is not fully relieved in the low-temperature orthorhombic phase. The suppression of magnetic ordering by the remanent frustration is the key factor stabilizing the nonmagnetic singlet ground state in zero field. Temperature-dependent measurements in the applied field $H = 12$ T revealed that the long-range ordering persists up to temperatures significantly higher than the spin gap, indicating that this phase is not directly related to the singlet-triplet excitation. Combining our neutron diffraction results with the previously published phase diagram, we support the existence of an intermediate disordered phase as the first excitation from the nonmagnetic singlet ground state. Based on our results, we propose YbAl $_{3}$ C $_{3}$ as a material for studying the quantum phase transitions of heavy-fermion metals under the influence of geometrical frustration.
Cited by 22
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Cited by 61
- 2 April 2012
- Published by American Physical Society (APS) in Physical Review B
Muon spin relaxation and neutron scattering investigations of the noncentrosymmetric heavy-fermion antiferromagnet CeRhGe $_{3}$
by A. D. Hillier, D. T. Adroja, P. Manuel, V. K. Anand, J. W. Taylor, K. A. McEwen, B. D. Rainford, M. M. Koza
The magnetic ground state of CeRhGe $_{3}$ has been investigated using magnetic susceptibility, heat capacity, neutron diffraction, muon spin relaxation (μSR), and inelastic neutron scattering (INS) techniques. Our μSR study clearly reveals the presence of two frequencies below T $_{N 2}$ $=$ 7 K and three frequencies between 7 K and T $_{N 1}$ $=$ 14.5 K, indicating long-range magnetic ordering of the Ce $^{3 +}$ moment. The temperature dependence of the highest frequency follows a mean-field order parameter. Our powder neutron diffraction study at 1.5 K reveals the presence of magnetic Bragg peaks, indexed by the propagation vector k $=$ (0, 0, 3/4) with the Ce $^{3 +}$ magnetic moment ∼0.45(9) $μ_{B}$ along the $c$ axis. INS studies at 18 K (i.e., above T $_{N 1}$ ) show the presence of two well-defined crystal-field (CEF) excitations at 7.5 and 18 meV. At 10 and 4.5 K, a very small increase has been observed in the CEF excitation energies. At 100 K, both CEF excitations broaden and a broad quasielastic component has also been observed. Further, the low-energy INS study reveals the presence of a nearly temperature-independent quasielastic linewidth between 16 and 60 K, which indicates a Kondo temperature T $_{K}$ $=$ 12.6(3) K. The presence of well-defined CEF excitations in CeRhGe $_{3}$ suggests local moment magnetism and may explain the absence of pressure-induced superconductivity. Analyzing the INS data based on a CEF model, we have evaluated the CEF ground-state wave functions and ground-state moment. The observed small value of the ordered moment along the $c$ axis, deduced from the neutron diffraction data, contrasts with the ab-plane moment direction predicted by the single-ion CEF anisotropy and indicates the presence of two-ion anisotropic magnetic exchange interactions, which govern the direction of the moment.
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- 2 April 2012
- Published by American Physical Society (APS) in Physical Review B
Muon spin relaxation and neutron scattering investigations of the noncentrosymmetric heavy-fermion antiferromagnet CeRhGe $_{3}$
by A. D. Hillier, D. T. Adroja, P. Manuel, V. K. Anand, J. W. Taylor, K. A. McEwen, B. D. Rainford, M. M. Koza
The magnetic ground state of CeRhGe $_{3}$ has been investigated using magnetic susceptibility, heat capacity, neutron diffraction, muon spin relaxation (μSR), and inelastic neutron scattering (INS) techniques. Our μSR study clearly reveals the presence of two frequencies below T $_{N 2}$ $=$ 7 K and three frequencies between 7 K and T $_{N 1}$ $=$ 14.5 K, indicating long-range magnetic ordering of the Ce $^{3 +}$ moment. The temperature dependence of the highest frequency follows a mean-field order parameter. Our powder neutron diffraction study at 1.5 K reveals the presence of magnetic Bragg peaks, indexed by the propagation vector k $=$ (0, 0, 3/4) with the Ce $^{3 +}$ magnetic moment ∼0.45(9) $μ_{B}$ along the $c$ axis. INS studies at 18 K (i.e., above T $_{N 1}$ ) show the presence of two well-defined crystal-field (CEF) excitations at 7.5 and 18 meV. At 10 and 4.5 K, a very small increase has been observed in the CEF excitation energies. At 100 K, both CEF excitations broaden and a broad quasielastic component has also been observed. Further, the low-energy INS study reveals the presence of a nearly temperature-independent quasielastic linewidth between 16 and 60 K, which indicates a Kondo temperature T $_{K}$ $=$ 12.6(3) K. The presence of well-defined CEF excitations in CeRhGe $_{3}$ suggests local moment magnetism and may explain the absence of pressure-induced superconductivity. Analyzing the INS data based on a CEF model, we have evaluated the CEF ground-state wave functions and ground-state moment. The observed small value of the ordered moment along the $c$ axis, deduced from the neutron diffraction data, contrasts with the ab-plane moment direction predicted by the single-ion CEF anisotropy and indicates the presence of two-ion anisotropic magnetic exchange interactions, which govern the direction of the moment.
Cited by 61
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- 28 February 2012
- Published by AIP Publishing in Journal of Applied Physics
Inelastic neutron scattering study of UPd2Sn
by N. Magnani, K. Gofryk, D. T. Adroja, E. Colineau, J.-C. Griveau, K. A. McEwen, D. Kaczorowski, R. Caciuffo
We performed inelastic neutron scattering spectroscopy on the Heusler intermetallic compound ${UPd}_{2} Sn$ . The presence of a clear intramultiplet transition between the two lowest-lying $5 f$ electronic states of uranium was clarified, and is consistent with predictions made in the framework of a localized-electron model. The excess molar specific heat is well reproduced by a Schottky curve corresponding to the experimentally measured energy gap if a moderately enhanced electronic contribution is taken into account.
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- 28 February 2012
- Published by AIP Publishing in Journal of Applied Physics
Inelastic neutron scattering study of UPd2Sn
by N. Magnani, K. Gofryk, D. T. Adroja, E. Colineau, J.-C. Griveau, K. A. McEwen, D. Kaczorowski, R. Caciuffo
We performed inelastic neutron scattering spectroscopy on the Heusler intermetallic compound ${UPd}_{2} Sn$ . The presence of a clear intramultiplet transition between the two lowest-lying $5 f$ electronic states of uranium was clarified, and is consistent with predictions made in the framework of a localized-electron model. The excess molar specific heat is well reproduced by a Schottky curve corresponding to the experimentally measured energy gap if a moderately enhanced electronic contribution is taken into account.

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