Abstract
Neutron scattering, ac 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 nonmagnetic Zr ions. Antiferromagnetic spin correlations develop below 10 K but remain dynamic down to 40 mK, with a significant amount of magnetic susceptibility. These correlations extend over the length of two tetrahedra edges and grow to six nearest neighbors with the application of a 20-kOe magnetic field. Magnetic heat capacity revealed a correlation peak at 2 K, but no Pauling's residual entropy was observed. We propose that the disorder precludes the development of spin-ice correlations seen in the chemically ordered Dy2Ti2O7 compound, with fluctuating spins in a disordered, liquidlike state (albeit slow) which do not freeze into a canonical spin-glass state that one might intuitively expect.
| Original language | English |
|---|---|
| Article number | 214442 |
| Journal | Physical Review B |
| Volume | 99 |
| Issue number | 21 |
| DOIs | |
| State | Published - Jun 27 2019 |
| Externally published | Yes |
Funding
J.S.G. and C.W.W. would like to thank the Ministry of Science and Technology (MOST) of the Taiwan for financially supporting this research under Contract No. MOST 120–2739–M–213–001–MY3 and the support of SIKA-Neutron Program of MOST, and ANSTO staff for neutron beamtime assistance. R.S.F. acknowledges São Paulo research foundation (FAPESP) Grant No. 2015/16191-5 and National Council for Scientific and Technological Development (CNPq) Grant No. 429511/2018-3. F.M.V. acknowledges FAPESP Grant No. 2011/19941-4.