High pressure synthesis and characterization of the pyrochlore Dy2Pt2O7:A new spin ice material

• 来源期刊: 中国物理B（英文版）
• 关键词: Dy2Pt2O7 pyrochlore oxide spin ice high-pressure synthesis
• 年，卷（期）: 2020,（4）
• 页码范围: 130-135
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab7b58

摘要

The cubic pyrochlore Dy2Pt2O7 was synthesized under 4 GPa and 1000 °C 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 Dy2Ti2O7, including (1) a large effective moment 9.64 μB 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～4.5 μB 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.