Magnetization and Thermal Expansion Properties of Quantum Spin Ice Candidate Pr₂Zr₂O₇

Abstract

We report low-temperature magnetization and thermal expansion studies of single-crystal pyrochlore magnet Pr 2 Zr 2 O 7. The temperature dependence of the magnetic susceptibility shows no sign of magnetic ordering down to 2 K. The susceptibility exhibits Curie-Weiss behavior below 10 K, yielding an effective moment µ eff = 2.5 µ B and a Weiss temperature θ CW = 0.25 K. Under [111] magnetic fields, the field dependence of the magnetization exhibits a metamagnetic transition at B c = 2.1 T, indicating the transition from the spin-ice manifold to the polarized "3(1)-in,1(3)-out" state. The linear thermal expansion coefficient α measured along the [111] direction increases with decreasing temperature and forms a maximum at ~1.3 K. The observed maximum of α can possibly be attributed to the magneto-elastic coupling between magnetic monopoles and the lattice.