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تسجيل مستخدم جديدMechanism for the high Neel temperature in SrTcO_3
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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.
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We investigate the origin of the high Neel temperature recently found in Tc perovskites. The electronic structure in the magnetic state of SrTcO3 and its 3d analogue SrMnO3 is calculated within a framework combining band-structure and many-body metho
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