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Coulomb spin liquid in anion-disordered pyrochlore Tb2Hf2O7
Romain Sibille1,2, Elsa Lhotel3, Monica Ciomaga Hatnean4
1Laboratory for Scientific Developments and Novel Materials, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland. romain.sibille@psi.ch.
Nature Communications
|October 14, 2017
Summary
Structural disorder in rare-earth pyrochlore oxides like Tb2Hf2O7 can prevent magnetic order. This disorder induces a fluctuating Coulomb spin liquid, offering insights into quantum many-body physics.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Magnetism
Background:
- Rare-earth pyrochlore oxides exhibit geometrically frustrated magnetism due to their tetrahedral ion networks.
- These materials are models for studying correlated magnetic phases, including spin liquids and spin ices.
- The impact of structural disorder on these ground states remains an open question.
Purpose of the Study:
- Investigate the role of structural disorder in rare-earth pyrochlore oxides.
- Explore how disorder affects magnetic properties and ground states.
- Determine if disorder can stabilize exotic magnetic phases like quantum spin liquids.
Main Methods:
- Studied the pyrochlore material Tb2Hf2O7.
- Utilized the proximity to a defective fluorite structure transition to tune anion Frenkel disorder.
- Maintained cation order while introducing disorder.
Main Results:
- Demonstrated tunable anion Frenkel disorder in Tb2Hf2O7.
- Showed that disorder introduces quenched random crystal fields and disordered exchange interactions.
- Observed that disorder prevents long-range magnetic order at low temperatures.
- Induced a strongly fluctuating Coulomb spin liquid with defect-induced frozen magnetic degrees of freedom.
Conclusions:
- Structural disorder plays a crucial role in the magnetic behavior of pyrochlores.
- Tb2Hf2O7 serves as a model material for studying the effects of disorder on frustrated magnetism.
- Disorder can stabilize quantum spin liquid phases in pyrochlore systems.
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