Melting of Spin Ice state through structural disorder in Dy2Zr2O7

Abstract

Neutron scattering, a.c. magnetic susceptibility and specific heat studies have been carried out on polycrystalline Dy2Zr2O7. Unlike the pyrochlore spin ice Dy2Ti2O7, Dy2Zr2O7 crystallizes into the fluorite structure and the magnetic Dy3+ moments randomly reside on the corner-sharing tetrahedral sublattice with non-magnetic Zr ions. Antiferromagnetic spin correlations develop below 10 K but remain dynamic down to 40 mK. These correlations extend over the length of two tetrahedra edges and grow to 6 nearest neighbors with the application of a 20 kOe magnetic field. No Pauling's residual entropy was observed and by 8 K the full entropy expected for a two level system is released. We propose that the disorder melts the spin ice state seen in the chemically ordered Dy2Ti2O7 compound, but the spins remain dynamic in a disordered, liquid-like state and do not freeze into a glass-like state that one might intuitively expect.

15 pages, 7 figures

References in corpus (9)

• Dirac Strings and Magnetic Monopoles in Spin Ice Dy2Ti2O7
• Low Temperature Spin Freezing in Dy2Ti2O7 Spin Ice
• Definitive Evidence for Order-by-Quantum-Disorder in Er2Ti2O7
• Spin Freezing in Geometrically Frustrated Antiferromagnets with Weak Disorder
• Disordered Route to the Coulomb Quantum Spin Liquid: Random Transverse Fields on Spin Ice in Pr${}_2$Zr${}_2$O${}_7$
• Structural and Magnetic Investigations of Single-Crystals of the Neodymium Zirconate Pyrochlore, Nd2Zr2O7
• Physical properties of a candidate quantum spin-ice system Pr2Hf2O7
• Evidence for the Confinement of Magnetic Monopoles in Quantum Spin Ice
• Optimization of single crystal growth of candidate quantum spin-ice Pr2Hf2O7 by optical floating-zone method