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Title: Local-Ising-type magnetic order and metamagnetism in the rare-earth pyrogermanate Er 2 Ge 2 O 7

Abstract

The recent discoveries of proximate quantum spin-liquid compounds and their potential application in quantum computing informs the search for new candidate materials for quantum spin-ice and spin-liquid physics. While the majority of such work has centered on members of the pyrochlore family due to their inherently frustrated linked tetrahedral structure, the rare-earth pyrogermanates also show promise for possible frustrated magnetic behavior. With the familiar stoichiometry R 2Ge 2O 7, these compounds generally have tetragonal symmetry with a rare-earth sublattice built of a spiral of alternating edge and corner-sharing rare-earth site triangles. Studies on Dy 2Ge 2O 7 and Ho 2Ge 2O 7 have shown tunable low temperature antiferromagnetic order, a high frustration index, and spin-ice-like dynamics. Here we use neutron diffraction to study magnetic order in Er 2Ge 2O 7 (space group P4 12 12) and find the lowest yet Neél temperature in the pyrogermanates of 1.15 K. Using neutron powder diffraction, we find the magnetic structure to order with k=(0,0,0) ordering vector, magnetic space group symmetry P4' 12 12', and a refined Er moment of m=8.1μ B near the expected value for the Er 3+ free ion. Provocatively, the magnetic structure exhibits similar “local Ising” behavior to that seenmore » in the pyrocholres where the Er moment points up or down along the short Er-Er bond. Upon applying a magnetic field, we find a first-order metamagnetic transition at ~0.35T to a lower symmetry P2' 12' 12 structure. This magnetic transition involves an inversion of Er moments aligned antiparallel to the applied field describing a class I spin-flip-type transition, indicating a strong local anisotropy at the Er site—reminiscent of that seen in the spin-ice pyrochlores.« less

Authors:
ORCiD logo [1];  [2];  [3]; ORCiD logo [4]; ORCiD logo [1]; ORCiD logo [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division; Clemson Univ., SC (United States). Dept. of Chemistry
  3. Clemson Univ., SC (United States). Dept. of Chemistry
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1490717
Alternate Identifier(s):
OSTI ID: 1490561
Grant/Contract Number:  
AC05-00OR22725; SC0014271
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review Materials
Additional Journal Information:
Journal Volume: 3; Journal Issue: 1; Journal ID: ISSN 2475-9953
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Taddei, Keith M., Sanjeewa, Liurukara D., Kolis, Joseph W., Sefat, Athena Safa, Dela Cruz, Clarina R., and Pajerowski, Daniel M. Local-Ising-type magnetic order and metamagnetism in the rare-earth pyrogermanate Er2Ge2O7. United States: N. p., 2019. Web. doi:10.1103/physrevmaterials.3.014405.
Taddei, Keith M., Sanjeewa, Liurukara D., Kolis, Joseph W., Sefat, Athena Safa, Dela Cruz, Clarina R., & Pajerowski, Daniel M. Local-Ising-type magnetic order and metamagnetism in the rare-earth pyrogermanate Er2Ge2O7. United States. doi:10.1103/physrevmaterials.3.014405.
Taddei, Keith M., Sanjeewa, Liurukara D., Kolis, Joseph W., Sefat, Athena Safa, Dela Cruz, Clarina R., and Pajerowski, Daniel M. Fri . "Local-Ising-type magnetic order and metamagnetism in the rare-earth pyrogermanate Er2Ge2O7". United States. doi:10.1103/physrevmaterials.3.014405.
@article{osti_1490717,
title = {Local-Ising-type magnetic order and metamagnetism in the rare-earth pyrogermanate Er2Ge2O7},
author = {Taddei, Keith M. and Sanjeewa, Liurukara D. and Kolis, Joseph W. and Sefat, Athena Safa and Dela Cruz, Clarina R. and Pajerowski, Daniel M.},
abstractNote = {The recent discoveries of proximate quantum spin-liquid compounds and their potential application in quantum computing informs the search for new candidate materials for quantum spin-ice and spin-liquid physics. While the majority of such work has centered on members of the pyrochlore family due to their inherently frustrated linked tetrahedral structure, the rare-earth pyrogermanates also show promise for possible frustrated magnetic behavior. With the familiar stoichiometry R2Ge2O7, these compounds generally have tetragonal symmetry with a rare-earth sublattice built of a spiral of alternating edge and corner-sharing rare-earth site triangles. Studies on Dy2Ge2O7 and Ho2Ge2O7 have shown tunable low temperature antiferromagnetic order, a high frustration index, and spin-ice-like dynamics. Here we use neutron diffraction to study magnetic order in Er2Ge2O7 (space group P41212) and find the lowest yet Neél temperature in the pyrogermanates of 1.15 K. Using neutron powder diffraction, we find the magnetic structure to order with k=(0,0,0) ordering vector, magnetic space group symmetry P4'1212', and a refined Er moment of m=8.1μB near the expected value for the Er3+ free ion. Provocatively, the magnetic structure exhibits similar “local Ising” behavior to that seen in the pyrocholres where the Er moment points up or down along the short Er-Er bond. Upon applying a magnetic field, we find a first-order metamagnetic transition at ~0.35T to a lower symmetry P2'12'12 structure. This magnetic transition involves an inversion of Er moments aligned antiparallel to the applied field describing a class I spin-flip-type transition, indicating a strong local anisotropy at the Er site—reminiscent of that seen in the spin-ice pyrochlores.},
doi = {10.1103/physrevmaterials.3.014405},
journal = {Physical Review Materials},
number = 1,
volume = 3,
place = {United States},
year = {2019},
month = {1}
}

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Works referenced in this record:

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