标题： SrTcO_3 的高尼尔温度机制 显示英文标题

标题： Mechanism for the high Neel temperature in SrTcO_3

摘要： 实验观察到的SrTcO_3中高奈尔温度(T_N)的微观起源，已通过第一性原理电子结构计算和多带Hubbard模型的平均场解相结合的方法进行了研究。 发现G型反铁磁态在参数空间的较大区域内具有鲁棒性，令人惊讶的是，在原子内交换相互作用强度较小以及带宽较大的情况下也发现了较大的稳定化能。 其微观起源可追溯至过渡金属位点的d3配置相关的特定方面。 考虑到适用于SrTcO_3及其相应的3d氧化物SrMnO_3的相互作用强度，我们发现T_N的比率为4:1，并且数值与实验结果一致。 显示英文摘要

摘要： The microscopic origin of the high Neel temperature (T_N) observed experimentally in SrTcO_3 has been examined using a combination of ab-initio electronic structure calculations and mean-field solutions of a multiband Hubbard model. The G-type antiferromagnetic state is found to be robust for a large region of parameter space, with large stabilization energies found, surprisingly, for small values of intraatomic exchange interaction strength as well as large bandwidths. The microscopic origin of this is traced to specific aspects associated with the d3 configuration at the transition-metal site. Considering values of interaction strengths appropriate for SrTcO3 and the corresponding 3d oxide SrMnO_3, we find a ratio of 4:1 for the TN as well as magnitudes consistent with experiment.