Physical properties of a candidate quantum spin-ice system Pr2Hf2O7

Abstract

Physical properties of a pyrohafnate compound Pr2Hf2O7 have been investigated by ac magnetic susceptibility χ_ ac(T), dc magnetic susceptibility χ(T), isothermal magnetization M(H) and heat capacity C_p(T) measurements on polycrystalline as well as single crystal samples combined with high-resolution synchrotron x-ray diffraction (XRD) for structural characterization and inelastic neutron scattering (INS) to determine the crystal field energy level scheme and wave functions. Synchrotron XRD data confirm the ordered cubic pyrochlore (Fd-3m) structure without any noticeable site mixing or oxygen deficiency. No clear evidence of long range magnetic ordering is observed down to 90 mK, however the χ_ac(T) evinces slow spin dynamics revealed by a frequency dependent broad peak associated with spin freezing. The INS data reveal the expected five well defined magnetic excitations due to crystal field splitting of the J = 4 ground state multiplet of the Pr^3+. The crystal field parameters and ground state wavefunction of Pr^3+ have been determined. The Ising anisotropic nature of magnetic ground state is inferred from the INS as well as χ(T) and M(H) data. Together these properties make Pr2Hf2O7 a candidate compound for quantum spin-ice behavior.

12 pages, 10 figures, 2 tables

References in corpus (3)

• Dirac Strings and Magnetic Monopoles in Spin Ice Dy2Ti2O7
• Dynamically-Induced Frustration as a Route to a Quantum Spin Ice State in Tb2Ti2O7 via Virtual Crystal Field Excitations and Quantum Many-Body Effects
• An anisotropic local modification of crystal field levels in Pr-based pyrochlores: a muon-induced effect modelled using density functional theory

Cited by in corpus (4)

• Melting of Spin Ice state through structural disorder in Dy2Zr2O7
• Muon spin relaxation and inelastic neutron scattering investigations of all-in/all-out antiferromagnet Nd2Hf2O7
• Single crystal growth, structure and magnetic properties of Pr2Hf2O7 pyrochlore
• Long-range dynamical magnetic order and spin tunneling in the cooperative paramagnetic states of the pyrochlore analogous spinel antiferromagnets CdYb2X4 (X = S, Se)