Magnetic structure and exchange interactions in the Heisenberg pyrochlore antiferromagnet Gd2 Pt2 O7

Philip G. Welch; Joseph A.M. Paddison; Manh Duc Le; Jason S. Gardner; Wei Tin Chen; Andrew R. Wildes; Andrew L. Goodwin; J. Ross Stewart

doi:10.1103/PhysRevB.105.094402

Magnetic structure and exchange interactions in the Heisenberg pyrochlore antiferromagnet Gd2 Pt2 O7

Philip G. Welch, Joseph A.M. Paddison, Manh Duc Le, Jason S. Gardner, Wei Tin Chen, Andrew R. Wildes, Andrew L. Goodwin, J. Ross Stewart

Research output: Contribution to journal › Article › peer-review

6 Scopus citations

Abstract

The Heisenberg pyrochlore antiferromagnet Gd2Pt2O7 is one of a series of gadolinium pyrochlore compounds with a variety of B-site cations. Despite the expected simplicity of a spin-only Gd3+ Heisenberg interaction model, the gadolinium pyrochlore series exhibits various complex magnetic ground states at low temperature. Gd2Pt2O7 displays the highest temperature magnetic order of the series with TN=1.6 K, which has been attributed to enhanced superexchange pathways facilitated by empty 5deg Pt orbitals. In this study, we use various neutron scattering techniques on an isotopically enriched polycrystalline Gd1602Pt2O7 sample to examine the magnetic structure and spin-wave excitation spectrum below TN in order to extract the dominant exchange interactions. We find that the ground-state magnetic structure is the Palmer-Chalker state previously seen in Gd2Sn2O7 with an associated gapped excitation spectrum consistent with enhanced exchange interactions between further near-neighbor Gd3+ ions. We confirm this exchange model with analysis of the magnetic diffuse scattering in the paramagnetic regime using polarized neutrons.

Original language	English
Article number	094402
Journal	Physical Review B
Volume	105
Issue number	9
DOIs	https://doi.org/10.1103/PhysRevB.105.094402
State	Published - Mar 1 2022

Funding

The authors would like to gratefully acknowledge the technical and support staff of both the ILL and ISIS, including Xavier Tonon and Chris Lawson, for cryogenic support. We acknowledge ISIS Xpress and Diamond BAG beam time on Polaris and I11, and we are indebted to Ron Smith and Simon Cassidy for conducting these measurements. J.R.S. acknowledges valuable discussions with Lucy Clark and David Voneshen. This work was supported by the UKRI: Engineering and Physical Sciences Research Council and the Science and Facilities Research Council. A portion of this work was supported by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the U.S. Department of Energy.

Funders	Funder number
Science and Facilities Research Council
U.S. Department of Energy
Oak Ridge National Laboratory
UK Research and Innovation
UT-Battelle
Engineering and Physical Sciences Research Council

Access to Document

10.1103/PhysRevB.105.094402

Cite this

@article{8306186bf4d84c0aa3ef3485f07b9c29,

title = "Magnetic structure and exchange interactions in the Heisenberg pyrochlore antiferromagnet Gd2 Pt2 O7",

abstract = "The Heisenberg pyrochlore antiferromagnet Gd2Pt2O7 is one of a series of gadolinium pyrochlore compounds with a variety of B-site cations. Despite the expected simplicity of a spin-only Gd3+ Heisenberg interaction model, the gadolinium pyrochlore series exhibits various complex magnetic ground states at low temperature. Gd2Pt2O7 displays the highest temperature magnetic order of the series with TN=1.6 K, which has been attributed to enhanced superexchange pathways facilitated by empty 5deg Pt orbitals. In this study, we use various neutron scattering techniques on an isotopically enriched polycrystalline Gd1602Pt2O7 sample to examine the magnetic structure and spin-wave excitation spectrum below TN in order to extract the dominant exchange interactions. We find that the ground-state magnetic structure is the Palmer-Chalker state previously seen in Gd2Sn2O7 with an associated gapped excitation spectrum consistent with enhanced exchange interactions between further near-neighbor Gd3+ ions. We confirm this exchange model with analysis of the magnetic diffuse scattering in the paramagnetic regime using polarized neutrons.",

author = "Welch, {Philip G.} and Paddison, {Joseph A.M.} and Le, {Manh Duc} and Gardner, {Jason S.} and Chen, {Wei Tin} and Wildes, {Andrew R.} and Goodwin, {Andrew L.} and Stewart, {J. Ross}",

note = "Publisher Copyright: {\textcopyright} 2022 American Physical Society.",

year = "2022",

month = mar,

day = "1",

doi = "10.1103/PhysRevB.105.094402",

language = "English",

volume = "105",

journal = "Physical Review B",

issn = "2469-9950",

publisher = "American Physical Society",

number = "9",

}

TY - JOUR

T1 - Magnetic structure and exchange interactions in the Heisenberg pyrochlore antiferromagnet Gd2 Pt2 O7

AU - Welch, Philip G.

AU - Paddison, Joseph A.M.

AU - Le, Manh Duc

AU - Gardner, Jason S.

AU - Chen, Wei Tin

AU - Wildes, Andrew R.

AU - Goodwin, Andrew L.

AU - Stewart, J. Ross

PY - 2022/3/1

Y1 - 2022/3/1

N2 - The Heisenberg pyrochlore antiferromagnet Gd2Pt2O7 is one of a series of gadolinium pyrochlore compounds with a variety of B-site cations. Despite the expected simplicity of a spin-only Gd3+ Heisenberg interaction model, the gadolinium pyrochlore series exhibits various complex magnetic ground states at low temperature. Gd2Pt2O7 displays the highest temperature magnetic order of the series with TN=1.6 K, which has been attributed to enhanced superexchange pathways facilitated by empty 5deg Pt orbitals. In this study, we use various neutron scattering techniques on an isotopically enriched polycrystalline Gd1602Pt2O7 sample to examine the magnetic structure and spin-wave excitation spectrum below TN in order to extract the dominant exchange interactions. We find that the ground-state magnetic structure is the Palmer-Chalker state previously seen in Gd2Sn2O7 with an associated gapped excitation spectrum consistent with enhanced exchange interactions between further near-neighbor Gd3+ ions. We confirm this exchange model with analysis of the magnetic diffuse scattering in the paramagnetic regime using polarized neutrons.

AB - The Heisenberg pyrochlore antiferromagnet Gd2Pt2O7 is one of a series of gadolinium pyrochlore compounds with a variety of B-site cations. Despite the expected simplicity of a spin-only Gd3+ Heisenberg interaction model, the gadolinium pyrochlore series exhibits various complex magnetic ground states at low temperature. Gd2Pt2O7 displays the highest temperature magnetic order of the series with TN=1.6 K, which has been attributed to enhanced superexchange pathways facilitated by empty 5deg Pt orbitals. In this study, we use various neutron scattering techniques on an isotopically enriched polycrystalline Gd1602Pt2O7 sample to examine the magnetic structure and spin-wave excitation spectrum below TN in order to extract the dominant exchange interactions. We find that the ground-state magnetic structure is the Palmer-Chalker state previously seen in Gd2Sn2O7 with an associated gapped excitation spectrum consistent with enhanced exchange interactions between further near-neighbor Gd3+ ions. We confirm this exchange model with analysis of the magnetic diffuse scattering in the paramagnetic regime using polarized neutrons.

UR - http://www.scopus.com/inward/record.url?scp=85126480272&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.105.094402

DO - 10.1103/PhysRevB.105.094402

M3 - Article

AN - SCOPUS:85126480272

SN - 2469-9950

VL - 105

JO - Physical Review B

JF - Physical Review B

IS - 9

M1 - 094402

ER -

Magnetic structure and exchange interactions in the Heisenberg pyrochlore antiferromagnet Gd2 Pt2 O7

Abstract

Funding

Access to Document

Other files and links

Fingerprint

Cite this