Route to high Neel temperatures in 4d and 5d transition metal oxides

There are very few magnetic members among the 4d and 5d transition metal oxides. In the present work, we examine the recent observation of a high Neel temperature T-N in the 4d oxides SrTcO3 and CaTcO3. Considering a multiband Hubbard model, we find that T-N is larger in the limit of a large bandwidth and vanishingly small intra-atomic exchange interaction strength, contrary to our conventional understanding of magnetism. This is traced to specific aspects of the d(3) configuration at the transition metal site and the study reveals additional examples with high T-N.