Jess H. Brewer
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Research Interests
Jess H. Brewer has a total of 748 co-authors. Here are the top co-authors by number of shared publications:
- Jun Sugiyama
Neutron Science and Technology Center
54 shared publications - Graeme M. Luke
McMaster University
48 shared publications E. J. Ansaldo
TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 Canada
44 shared publicationsR. F. Kiefl
Canadian Institute for Advanced Research, 180 Dundas Street West, Toronto, Ontario, Canada, M5G 1Z8
42 shared publicationsS. R. Kreitzman
TRIUMF, Canadian Institute for Advanced Research and Department of Physics, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
41 shared publicationsT. M. Riseman
Superconductivity Research Group, University of Birmingham, Birmingham B15 2TT, United Kingdom
36 shared publications
Latest Publications
- Open Access
- 11 November 2020
- Published by American Physical Society (APS) in Physical Review B
- Vol. 102 (18) , 184412
Revisiting the -type antiferromagnet with muon spin rotation measurements and density functional theory calculationsAn -type antiferromagnet, , was examined by means of positive muon spin rotation and relaxation () measurements and first-principles calculations based on a density functional theory (DFT). Below K, a clear muon spin precession signal was observed in the time spectrum recorded under zero field, due to the formation of a static internal magnetic field. The microscopic origin of such an internal field was computed as a sum of dipolar and hyperfine contact fields at the site (0.624, 0, 0.854), where both the muon site and the local spin density at such a site were predicted with DFT calculations. While the computed values were consistent with experimentally obtained ones, in both the antiferromagnetic and the paramagnetic states, the contribution of the hyperfine contact field was shown to be insignificant even below . Finally, measurements at higher temperatures signified thermally activated Na-ion diffusion with meV and /s, commonly observed in layered-type compounds.- 11 November 2020
- Published by American Physical Society (APS) in Physical Review B
- Vol. 102 (18) , 184412
Open AccessRevisiting the -type antiferromagnet with muon spin rotation measurements and density functional theory calculationsAn -type antiferromagnet, , was examined by means of positive muon spin rotation and relaxation () measurements and first-principles calculations based on a density functional theory (DFT). Below K, a clear muon spin precession signal was observed in the time spectrum recorded under zero field, due to the formation of a static internal magnetic field. The microscopic origin of such an internal field was computed as a sum of dipolar and hyperfine contact fields at the site (0.624, 0, 0.854), where both the muon site and the local spin density at such a site were predicted with DFT calculations. While the computed values were consistent with experimentally obtained ones, in both the antiferromagnetic and the paramagnetic states, the contribution of the hyperfine contact field was shown to be insignificant even below . Finally, measurements at higher temperatures signified thermally activated Na-ion diffusion with meV and /s, commonly observed in layered-type compounds. - Open Access
- 29 July 2020
- Published by American Physical Society (APS) in Physical Review Research
- Vol. 2 (3) , 033161
Lithium diffusion in detected withPositive- and negative-muon spin rotation and relaxation () was first used to investigate fluctuations of nuclear magnetic fields in an olivine-type battery material, , in order to clarify the diffusive species, namely, to distinguish between a hopping among interstitial sites and ions diffusing in the lattice. Muon diffusion can only occur in , because the implanted forms a stable muonic atom at the lattice site, and therefore any change in linewidth measured with must be due to diffusion. Since the two measurements exhibit a similar increase in the field fluctuation rate with temperature above 100 K, it is confirmed that ions are in fact diffusing. The diffusion coefficient of at 300 K and its activation energy were estimated to be and 0.19(3) eV, respectively. Such combined measurements are thus shown to be a suitable tool for detecting ion diffusion in solid-state energy materials.- 29 July 2020
- Published by American Physical Society (APS) in Physical Review Research
- Vol. 2 (3) , 033161
Open AccessLithium diffusion in detected withPositive- and negative-muon spin rotation and relaxation () was first used to investigate fluctuations of nuclear magnetic fields in an olivine-type battery material, , in order to clarify the diffusive species, namely, to distinguish between a hopping among interstitial sites and ions diffusing in the lattice. Muon diffusion can only occur in , because the implanted forms a stable muonic atom at the lattice site, and therefore any change in linewidth measured with must be due to diffusion. Since the two measurements exhibit a similar increase in the field fluctuation rate with temperature above 100 K, it is confirmed that ions are in fact diffusing. The diffusion coefficient of at 300 K and its activation energy were estimated to be and 0.19(3) eV, respectively. Such combined measurements are thus shown to be a suitable tool for detecting ion diffusion in solid-state energy materials. - 26 February 2020
- Published by American Physical Society (APS) in Physical Review B
- Vol. 101 (7) , 077201
Comment on “Role of the transition state in muon implantation” and “Thermal spike in muon implantation”
Vilão et al. ( Phys. Rev. B 96, 195205 (2017) and Phys. Rev. B 99, 195206 (2019)) have reported positive muon spin rotation/relaxation () experiments on various insulating metal oxides, solar cell materials, and alloyed Ge. They note the presence of a separate early component in the polarization time dependence which relaxes more rapidly than the longer lived signal and also exhibits (in :Mg) a slightly increased frequency at low temperature in transverse field. They interpret this early component as a weakly bound “transition state” of the neutral muonium () atom formed epithermally by the incoming 4-MeV muon, in which the hyperfine interaction between the muon and the electron is “motionally narrowed” by rapid spin exchange, resulting in a “diamagneticlike” Larmor precession signal. This “diamagneticlike transition state” supposedly takes microseconds to relax into its final ground state due to the reluctance of the surrounding lattice to deform around the Mu atom. However, numerous earlier experiments (including those in electric fields) on various liquids and solids ranging from wide-gap insulators to narrow-gap semiconductors have convincingly shown that Mu formation proceeds through capture of radiolysis electrons by thermalized muons—a process crucially dependent on the electron mobility rather than epithermal dynamics. Therefore, we question the validity of the interpretation by Vilão et al. and raise some important issues that need clarification.- 26 February 2020
- Published by American Physical Society (APS) in Physical Review B
- Vol. 101 (7) , 077201
Comment on “Role of the transition state in muon implantation” and “Thermal spike in muon implantation”
Vilão et al. ( Phys. Rev. B 96, 195205 (2017) and Phys. Rev. B 99, 195206 (2019)) have reported positive muon spin rotation/relaxation () experiments on various insulating metal oxides, solar cell materials, and alloyed Ge. They note the presence of a separate early component in the polarization time dependence which relaxes more rapidly than the longer lived signal and also exhibits (in :Mg) a slightly increased frequency at low temperature in transverse field. They interpret this early component as a weakly bound “transition state” of the neutral muonium () atom formed epithermally by the incoming 4-MeV muon, in which the hyperfine interaction between the muon and the electron is “motionally narrowed” by rapid spin exchange, resulting in a “diamagneticlike” Larmor precession signal. This “diamagneticlike transition state” supposedly takes microseconds to relax into its final ground state due to the reluctance of the surrounding lattice to deform around the Mu atom. However, numerous earlier experiments (including those in electric fields) on various liquids and solids ranging from wide-gap insulators to narrow-gap semiconductors have convincingly shown that Mu formation proceeds through capture of radiolysis electrons by thermalized muons—a process crucially dependent on the electron mobility rather than epithermal dynamics. Therefore, we question the validity of the interpretation by Vilão et al. and raise some important issues that need clarification.- Open Access
- 29 January 2019
- Published by Royal Society of Chemistry (RSC) in Sustainable Energy & Fuels
- Vol. 3 (4) , 956-964
Desorption reaction in MgH2 studied with in situ μ+SR
To study the mechanism determining the desorption temperature of hydrogen storage materials, we have measured muon spin rotation and relaxation (μ+SR) in MgH2 together with the pressure in the sample space.
- 29 January 2019
- Published by Royal Society of Chemistry (RSC) in Sustainable Energy & Fuels
- Vol. 3 (4) , 956-964
Open AccessDesorption reaction in MgH2 studied with in situ μ+SR
To study the mechanism determining the desorption temperature of hydrogen storage materials, we have measured muon spin rotation and relaxation (μ+SR) in MgH2 together with the pressure in the sample space.
- Open Access
- 24 November 2015
- Published by Frontiers Media SA in Frontiers in Physics
- Vol. 3
Book Review: Spintronics-Based Computing
Book Review: Spintronics-Based Computing
- 24 November 2015
- Published by Frontiers Media SA in Frontiers in Physics
- Vol. 3
Open AccessBook Review: Spintronics-Based Computing
Book Review: Spintronics-Based Computing
- Open Access
- 16 September 2015
- Published by Springer Nature in Scientific Reports
- Vol. 5 (1) , srep14156
Signatures of new d-wave vortex physics in overdoped Tl2Ba2CuO6+x revealed by TF-µ+SR
The spontaneous expulsion of applied magnetic field, the Meissner effect, is a defining feature of superconductors; in Type-II superconductors above the lower critical field, this screening takes the form of a lattice of magnetic flux vortices. Using implanted spin-1/2 positive muons, one can measure the vortex lattice field distribution through the spin precession and deduce key parameters of the superconducting ground state, and thereby fundamental properties of the superconducting pairing. Muon spin rotation/relaxation (µSR) experiments have indeed revealed much interesting physics in the underdoped cuprates, where superconductivity is closely related to, or coexistent with, disordered or fluctuating magnetic and charge excitations. Such complications should be absent in overdoped cuprates, which are believed to exhibit conventional Fermi liquid behaviour. These first transverse field (TF)-µ+SR experiments on heavily-overdoped single crystals reveal a superfluid density exhibiting a clear inflection point near 0.5Tc , with a striking doping-independent scaling. This reflects hitherto unrecognized physics intrinsic to d-wave vortices, evidently generic to the cuprates, and may offer fundamentally new insights into their still-mysterious superconductivity.
- 16 September 2015
- Published by Springer Nature in Scientific Reports
- Vol. 5 (1) , srep14156
Open AccessSignatures of new d-wave vortex physics in overdoped Tl2Ba2CuO6+x revealed by TF-µ+SR
The spontaneous expulsion of applied magnetic field, the Meissner effect, is a defining feature of superconductors; in Type-II superconductors above the lower critical field, this screening takes the form of a lattice of magnetic flux vortices. Using implanted spin-1/2 positive muons, one can measure the vortex lattice field distribution through the spin precession and deduce key parameters of the superconducting ground state, and thereby fundamental properties of the superconducting pairing. Muon spin rotation/relaxation (µSR) experiments have indeed revealed much interesting physics in the underdoped cuprates, where superconductivity is closely related to, or coexistent with, disordered or fluctuating magnetic and charge excitations. Such complications should be absent in overdoped cuprates, which are believed to exhibit conventional Fermi liquid behaviour. These first transverse field (TF)-µ+SR experiments on heavily-overdoped single crystals reveal a superfluid density exhibiting a clear inflection point near 0.5Tc , with a striking doping-independent scaling. This reflects hitherto unrecognized physics intrinsic to d-wave vortices, evidently generic to the cuprates, and may offer fundamentally new insights into their still-mysterious superconductivity.
- Open AccessSignatures of New $d$-Wave Vortex Physics in Overdoped Tl$_2$Ba$_2$CuO$_{6+x}$ Revealed by TF-$μ^+$SR
The spontaneous expulsion of applied magnetic field, the Meissner effect, is a defining feature of superconductors; in Type-II superconductors above the lower critical field, this screening takes the form of a lattice of magnetic flux vortices. Using implanted spin-1/2 positive muons, one can measure the vortex lattice field distribution through the spin precession and deduce key parameters of the superconducting ground state, and thereby fundamental properties of the superconducting pairing. Muon spin rotation/relaxation ($\mu$SR) experiments have indeed revealed much interesting physics in the underdoped cuprates, where superconductivity is closely related to, or coexistent with, disordered or fluctuating magnetic and charge excitations. Such complications should be absent in overdoped cuprates, which are believed to exhibit conventional Fermi liquid behaviour. These first transverse field (TF)-$\mu^+$SR experiments on heavily-overdoped single crystals reveal a superfluid density exhibiting a clear inflection point near 0.5$T_c$, with a striking doping-independent scaling. This reflects hitherto unrecognized physics intrinsic to $d$-wave vortices, evidently generic to the cuprates, and may offer fundamentally new insights into their still-mysterious superconductivity.
Open AccessSignatures of New $d$-Wave Vortex Physics in Overdoped Tl$_2$Ba$_2$CuO$_{6+x}$ Revealed by TF-$μ^+$SRThe spontaneous expulsion of applied magnetic field, the Meissner effect, is a defining feature of superconductors; in Type-II superconductors above the lower critical field, this screening takes the form of a lattice of magnetic flux vortices. Using implanted spin-1/2 positive muons, one can measure the vortex lattice field distribution through the spin precession and deduce key parameters of the superconducting ground state, and thereby fundamental properties of the superconducting pairing. Muon spin rotation/relaxation ($\mu$SR) experiments have indeed revealed much interesting physics in the underdoped cuprates, where superconductivity is closely related to, or coexistent with, disordered or fluctuating magnetic and charge excitations. Such complications should be absent in overdoped cuprates, which are believed to exhibit conventional Fermi liquid behaviour. These first transverse field (TF)-$\mu^+$SR experiments on heavily-overdoped single crystals reveal a superfluid density exhibiting a clear inflection point near 0.5$T_c$, with a striking doping-independent scaling. This reflects hitherto unrecognized physics intrinsic to $d$-wave vortices, evidently generic to the cuprates, and may offer fundamentally new insights into their still-mysterious superconductivity.
- Open Access
- 16 December 2014
- Published by IOP Publishing in Journal of Physics: Conference Series
- Vol. 551 (1) , 012030
TF-μ+SR in overdoped Tl2Ba2CuO6+x: simplicity still elusive
Encouraged by predictions of simple Fermi liquid behavior in the overdoped versions of high temperature superconductors (HTcSC) based on CuO2 planes, we have performed TF-μ+ SR experiments on several high quality oriented crystal mosaics of Tl2Ba2CuO6+x ("Tl-2201") in the vortex-lattice state where the magnetic penetration depth λ can be extracted from the characteristic superconducting (SC) lineshape by χ2-minimization fitting in the time domain. The results show evidence for a surprising degree of disorder, causing some "smearing" of the characteristic lineshape features, but we were able to extract λ as a function of temperature, revealing a remarkably consistent T-dependence of the SC carrier density ns ∝ λ−2 that suggests this "role-model cuprate" is anything but "simple". The extracted superfluid density for all dopings exhibits a clear inflection point with temperature, suggesting a vortex lattice transition. Such a transition would have important implications for other measurements.
- 16 December 2014
- Published by IOP Publishing in Journal of Physics: Conference Series
- Vol. 551 (1) , 012030
Open AccessTF-μ+SR in overdoped Tl2Ba2CuO6+x: simplicity still elusive
Encouraged by predictions of simple Fermi liquid behavior in the overdoped versions of high temperature superconductors (HTcSC) based on CuO2 planes, we have performed TF-μ+ SR experiments on several high quality oriented crystal mosaics of Tl2Ba2CuO6+x ("Tl-2201") in the vortex-lattice state where the magnetic penetration depth λ can be extracted from the characteristic superconducting (SC) lineshape by χ2-minimization fitting in the time domain. The results show evidence for a surprising degree of disorder, causing some "smearing" of the characteristic lineshape features, but we were able to extract λ as a function of temperature, revealing a remarkably consistent T-dependence of the SC carrier density ns ∝ λ−2 that suggests this "role-model cuprate" is anything but "simple". The extracted superfluid density for all dopings exhibits a clear inflection point with temperature, suggesting a vortex lattice transition. Such a transition would have important implications for other measurements.
- 4 June 2013
- Published by Royal Society of Chemistry (RSC) in RSC Advances
- Vol. 3 (29) , 11634-11639
The gradient distribution of Ni ions in cation-disordered Li[Ni1/2Mn3/2]O4 clarified by muon-spin rotation and relaxation (μSR)
Cation-ordered Li[Ni1/2Mn3/2]O4 with a P4332 space group (CO-LNMO) and “cation-disordered” (CDO) LNMO are thought to be the state-of-the-art materials for lithium-ion batteries. However, in contrast to CO-LNMO, the crystal structure and electrochemical reaction scheme of CDO-LNMO are not fully understood. We have measured the muon-spin rotation and relaxation (μSR) spectra for samples of both CO-LNMO and CDO-LNMO, in particular at their magnetic transition temperatures (TC) below 130 K. The weak transverse field (wTF) μSR measurements reveal that the range of TC for the CDO-LNMO sample is very large (ΔTC ∼ 55 K) compared with that for the CO-LNMO sample (ΔTC < 5 K). This suggests an inhomogeneous cation distribution in the CDO-LNMO sample, because the sample consists of multiple phases with different TC. Based on the wTF-μSR result for stoichiometric LiMn2O4, we have proposed that CDO-LNMO is a mixture of Li[Ni1/2−ωMn3/2+ω]O4 and LiMn2O4.
- 4 June 2013
- Published by Royal Society of Chemistry (RSC) in RSC Advances
- Vol. 3 (29) , 11634-11639
The gradient distribution of Ni ions in cation-disordered Li[Ni1/2Mn3/2]O4 clarified by muon-spin rotation and relaxation (μSR)
Cation-ordered Li[Ni1/2Mn3/2]O4 with a P4332 space group (CO-LNMO) and “cation-disordered” (CDO) LNMO are thought to be the state-of-the-art materials for lithium-ion batteries. However, in contrast to CO-LNMO, the crystal structure and electrochemical reaction scheme of CDO-LNMO are not fully understood. We have measured the muon-spin rotation and relaxation (μSR) spectra for samples of both CO-LNMO and CDO-LNMO, in particular at their magnetic transition temperatures (TC) below 130 K. The weak transverse field (wTF) μSR measurements reveal that the range of TC for the CDO-LNMO sample is very large (ΔTC ∼ 55 K) compared with that for the CO-LNMO sample (ΔTC < 5 K). This suggests an inhomogeneous cation distribution in the CDO-LNMO sample, because the sample consists of multiple phases with different TC. Based on the wTF-μSR result for stoichiometric LiMn2O4, we have proposed that CDO-LNMO is a mixture of Li[Ni1/2−ωMn3/2+ω]O4 and LiMn2O4.
- 14 February 2013
- Published by IOP Publishing in Journal of Physics: Condensed Matter
- Vol. 25 (11) , 115601
Observation of magnetic polarons in the magnetoresistive pyrochlore Lu2V2O7
Materials that exhibit colossal magnetoresistance (CMR) have attracted much attention due to their potential technological applications. One particularly interesting model for the magnetoresistance of low-carrier-density ferromagnets involves mediation by magnetic polarons (MP)-electrons localized in nanoscale ferromagnetic 'droplets' by their exchange interaction. However, MP have not previously been directly detected and their size has been difficult to determine from macroscopic measurements. In order to provide this crucial information, we have carried out muon spin rotation measurements on the magnetoresistive semiconductor Lu(2)V(2)O(7) in the temperature range from 2 to 300 K and in magnetic fields up to 7 T. Magnetic polarons with characteristic radius R ≈ 0.4 nm are detected below about 100 K, where Lu(2)V(2)O(7) exhibits CMR; at higher temperature, where the magnetoresistance vanishes, these MP also disappear. This observation confirms the MP-mediated model of CMR and reveals the microscopic size of the MP in magnetoresistive pyrochlores.
- 14 February 2013
- Published by IOP Publishing in Journal of Physics: Condensed Matter
- Vol. 25 (11) , 115601
Observation of magnetic polarons in the magnetoresistive pyrochlore Lu2V2O7
Materials that exhibit colossal magnetoresistance (CMR) have attracted much attention due to their potential technological applications. One particularly interesting model for the magnetoresistance of low-carrier-density ferromagnets involves mediation by magnetic polarons (MP)-electrons localized in nanoscale ferromagnetic 'droplets' by their exchange interaction. However, MP have not previously been directly detected and their size has been difficult to determine from macroscopic measurements. In order to provide this crucial information, we have carried out muon spin rotation measurements on the magnetoresistive semiconductor Lu(2)V(2)O(7) in the temperature range from 2 to 300 K and in magnetic fields up to 7 T. Magnetic polarons with characteristic radius R ≈ 0.4 nm are detected below about 100 K, where Lu(2)V(2)O(7) exhibits CMR; at higher temperature, where the magnetoresistance vanishes, these MP also disappear. This observation confirms the MP-mediated model of CMR and reveals the microscopic size of the MP in magnetoresistive pyrochlores.