Title: Dipolar-octupolar Ising antiferromagnetism in ${\text{Sm}}_2{\text{Ti}}_2{\text{O}}_7$ : A moment fragmentation candidate

Abstract

Over the past two decades, the magnetic ground states of all rare-earth titanate pyrochlores have been extensively studied, with the exception of ${\text{Sm}}_2{\text{Ti}}_2{\text{O}}_7$. This is, in large part, due to the very high absorption cross section of naturally occurring samarium, which renders neutron scattering infeasible. To combat this, we have grown a large, isotopically enriched single crystal of ${\text{Sm}}_2{\text{Ti}}_2{\text{O}}_7$. Using inelastic neutron scattering, we determine that the crystal field ground state for Sm3+ is a dipolar-octupolar doublet with Ising anisotropy. Neutron diffraction experiments reveal that ${\text{Sm}}_2{\text{Ti}}_2{\text{O}}_7$ orders into the all-in, all-out magnetic structure with an ordered moment of 0.44(7)μ_B below TN=0.35 K, consistent with expectations for antiferromagnetically coupled Ising spins on the pyrochlore lattice. Zero-field muon spin relaxation measurements reveal an absence of spontaneous oscillations and persistent spin fluctuations down to 0.03 K. In conclusion, the combination of the dipolar-octupolar nature of the Sm³⁺ moment, the all-in, all-out ordered state, and the low-temperature persistent spin dynamics make this material an intriguing candidate for moment fragmentation physics.

Authors:

Mauws, Cole ^[1]; Hallas, A. M. ^[2]; Sala, Gabriele  ^[3];

• Search DOE PAGES for author "Sala, Gabriele"
• Search DOE PAGES for ORCID "0000-0002-6654-0275"

Aczel, Adam A.  ^[3];

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• Search DOE PAGES for ORCID "0000-0003-1964-1943"

Sarte, P. M. ^[4]; Gaudet, J. ^[5]; Ziat, D. ^[6]; Quilliam, J. A. ^[6]; Lussier, J. A. ^[7]; Bieringer, M. ^[7]; Zhou, H. D. ^[8]; Wildes, A. ^[9]; Stone, Matthew B.  ^[3];

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Abernathy, Douglas L.  ^[3];

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• Search DOE PAGES for ORCID "0000-0002-3533-003X"

Luke, G. M. ^[10]; Gaulin, B. D. ^[11]; Wiebe, Christopher R. ^[12]

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+ Show Author Affiliations

1. Univ. of Manitoba, Winnipeg, Manitoba (Canada). Dept. of Chemistry; Univ. of Winnipeg, Winnipeg, Manitoba (Canada). Dept. of Chemistry
2. McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy; Rice Univ., Houston, TX (United States). Dept. of Physics and Astronomy and Rice Center for Quantum Materials
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division
4. Univ. of Edinburgh, Scotland (United Kingdom). School of Chemistry; Univ. of Edinburgh, Scotland (United Kingdom). Centre for Science at Extreme Conditions
5. McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy
6. Univ. de Sherbrooke, Sherbrooke, Québec (Canada). Inst. Quantique and Dépt. de Physique
7. Univ. of Manitoba, Winnipeg, Manitoba (Canada). Dept. of Chemistry
8. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy; Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab)
9. Inst. Laue-Langevin, Grenoble (France)
10. McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy; Canadian Inst. for Advanced Research, Toronto, Ontario (Canada); TRIUMF, Vancouver, BC (Canada)
11. McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy; Canadian Inst. for Advanced Research, Toronto, Ontario (Canada)
12. Univ. of Manitoba, Winnipeg, Manitoba (Canada). Dept. of Chemistry; Univ. of Winnipeg, Winnipeg, Manitoba (Canada). Dept. of Chemistry; McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy; Canadian Inst. for Advanced Research, Toronto, Ontario (Canada)

Publication Date:

Wed Sep 05 00:00:00 EDT 2018

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1470878

Alternate Identifier(s):

OSTI ID: 1468836

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review B

Additional Journal Information:

Journal Volume: 98; Journal Issue: 10; Journal ID: ISSN 2469-9950

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY