Los Alamos National Laboratory, MPA-CMMS, Los Alamos, NM, 87545, USA.
Florida State University, NHMFL, Tallahassee, FL, 32310, USA.
Sci Rep. 2017 Jun 20;7(1):3867. doi: 10.1038/s41598-017-03648-2.
Metamagnetism occuring inside a ferromagnetic phase is peculiar. Therefore, SrRuO, a T = 105 K ferromagnet, has attracted much attention in recent years, because it develops a pronounced metamagnetic anomaly below T for magnetic fields applied in the crystallographic ab-plane. The metamagnetic transition moves to higher fields for lower temperatures and splits into a double anomaly at critical fields H = 2.3 T and H = 2.8 T, respectively. Here, we report a detailed study of the different components of the magnetization vector as a function of temperature, applied magnetic field, and varying angle in SrRuO. We discover for the first time a reduction of the magnetic moment in the plane of rotation at the metamagnetic transition. The anomaly shifts to higher fields by rotating the field from H ⊥ c to H || c. We compare our experimental findings with numerical simulations based on spin reorientation models taking into account magnetocrystalline anisotropy, Zeeman effect and antisymmetric exchange interactions. While Magnetocrystalline anisotropy combined with a Zeeman term are sufficient to explain a metamagnetic transition in SrRuO, a Dzyaloshinskii-Moriya term is crucial to account for the reduction of the magnetic moment as observed in the experiments.
顺磁体中发生的反铁磁性是特殊的。因此，SrRuO，一种 T = 105 K 的铁磁体，近年来引起了广泛关注，因为它在晶体 ab 平面上施加磁场时，在 T 以下表现出明显的反铁磁异常。反铁磁转变向更高的场移动，温度越低，在临界场 H = 2.3 T 和 H = 2.8 T 处分裂为双异常。在这里，我们报告了对 SrRuO 中磁化矢量随温度、外加磁场和变化角度的不同分量的详细研究。我们首次发现反铁磁转变时在旋转平面上磁矩减小。通过将磁场从 H ⊥ c 旋转到 H || c，异常向更高的场移动。我们将实验结果与基于考虑磁晶各向异性、塞曼效应和反铁磁交换相互作用的自旋重定向模型的数值模拟进行了比较。虽然磁晶各向异性与塞曼项相结合足以解释 SrRuO 中的反铁磁转变，但为了解释实验中观察到的磁矩减小，Dzyaloshinskii-Moriya 项是至关重要的。
