Magnetization beyond the Ising limit of Ho2Ti2O7

Article

关键词: SPIN-ICE;    MONOPOLES;   

DOI  :  10.1103/PhysRevB.99.085132

来源: SCIE

【 摘 要 】

We report that the local Ising anisotropy in pyrochlore oxides-the crucial requirement for realizing the spin-ice state-can be broken by means of high magnetic fields. For the case of the well-established classical spin-ice compound Ho2Ti2O7 the magnetization exceeds the angle-dependent saturation value of the Ising limit using ultrahigh fields up to 120 T. However, even under such extreme magnetic fields full saturation cannot be achieved. Crystal-electric-field calculations reveal that a level crossing for two of the four ion positions leads to magnetization steps at 55 and 100 T. In addition, we show that by using a field sweep rate in the range of the spin-relaxation time the dynamics of the spin system can be probed. Exclusively at 25 ns/T, a new peak of the susceptibility appears around 2 T. We argue, this signals the crossover between spin-ice and polarized correlations.

【 授权许可】

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