摘要
The cubic pyrochlore Dy2Pt2O7 was synthesized under 4 GPa and 1000℃ and its magnetic and thermodynamic properties were characterized by DC and AC magnetic susceptibility and specific heat down to 0.1 K.We found that Dy2Pt2O7 does not form long-range magnetic order,but displays characteristics of canonical spin ice such as Dy2Pt2O7,including(1)a large effective moment 9.64μB close to the theoretical value and a small positive Curie-Weiss temperatureθCW=+0.77 K signaling a dominant ferromagnetic interaction among the Ising spins;(2)a saturation moment ~4.5μB being half of the total moment due to the local<111>Ising anisotropy;(3)thermally activated spin relaxation behaviors in the low(~1 K)and high(~20 K)temperature regions with different energy barriers and characteristic relaxation time;and most importantly,(4)the presence of a residual entropy close to Pauling’s estimation for water ice.
作者
崔琦
蔡云麒
李翔
顿志凌
孙培杰
周建十
周海东
程金光
Qi Cui;Yun-Qi Cai;Xiang Li;Zhi-Ling Dun;Pei-Jie Sun;Jian-Shi Zhou;Hai-Dong Zhou;Jin-Guang Cheng(Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China;Materials Science and Engineering Program,Mechanical Engineering,University of Texas at Austin,Austin,Texas 78712,USA;Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement of Ministry of Education,School of Physics,Beijing Institute of Technology,Beijing 100081,China;Department of Physics and Astronomy,University of Tennessee,Knoxville,TN 37996,USA;School of Physics,Georgia Institute of Technology,Atlanta,GA 30332,USA;Songshan Lake Materials Laboratory,Dongguan 523808,China)
基金
Project supported by the National Key R&D Program of China(Grant No.2018YFA0305700)
the National Natural Science Foundation of China(Grant Nos.11834016,11874400,and 11921004)
the Beijing Natural Science Foundation,China(Grant No.Z190008)
the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH013)
the CAS Interdisciplinary Innovation Team
support of Grant No.NSF-DMR-1350002
support of NSF DMR Grant No.1729588。
