论文标题
单轴压力对自旋冰HO2TI2O7的影响
Effects of uniaxial pressure on the spin ice Ho2Ti2O7
论文作者
论文摘要
自旋冰材料HO2TI2O7和DY2TI2O7是高度沮丧的磁性材料的实验性和理论示例。然而，对单轴压力的影响尚未得到充分研究，在这里我们报告了在[001]，[111]和[110]晶体方向上施加的单轴压力下HO2TI2O7的磁化测量值。基本特征是通过偶极自旋冰模型的扩展来捕获的。我们发现我们的模型与沿三个方向中两个施加的压力之间的测量之间有很好的匹配，并扩展了框架以讨论晶体错位对第三方向的影响。根据磁化测量结果确定的参数再现了我们在沿[110]晶体方向施加的单轴压力下执行的中子散射测量值。在详细的分析中，我们包括最近经过验证的电磁因子的敏感性依赖性。我们的工作证明了适度的施加压力来修改磁相互作用参数。知识可用于预测诱导沮丧的材料中新阶段和过渡所需的关键压力，在HO2TI2O7的情况下，我们希望过渡到超过3.3 GPA的单轴压力的铁磁基态。
The spin ice materials Ho2Ti2O7 and Dy2Ti2O7 are experimental and theoretical exemplars of highly frustrated magnetic materials. However, the effects of an applied uniaxial pressure are not well studied, and here we report magnetization measurements of Ho2Ti2O7 under uniaxial pressure applied in the [001], [111] and [110] crystalline directions. The basic features are captured by an extension of the dipolar spin ice model. We find a good match between our model and measurements with pressures applied along two of the three directions, and extend the framework to discuss the influence of crystal misalignment for the third direction. The parameters determined from the magnetization measurements reproduce neutron scattering measurements we perform under uniaxial pressure applied along the [110] crystalline direction. In the detailed analysis we include the recently verified susceptibility dependence of the demagnetizing factor. Our work demonstrates the application of a moderate applied pressure to modify the magnetic interaction parameters. The knowledge can be used to predict critical pressures needed to induce new phases and transitions in frustrated materials, and in the case of Ho2Ti2O7 we expect a transition to a ferromagnetic ground state for uniaxial pressures above 3.3 GPa.
