The effect of hydrogen ordering on the electronic and magnetic properties of the strontium vanadium oxyhydride

The electronic and magnetic properties of the recently fabricated strontium vanadium perovskite oxyhydride are investigated by ab initio calculations. The role of the unusually ordered hydrogen ions are carefully analyzed. The hydrogen ions break the crystal symmetry to change the degeneracy of the V t_2g orbit, thus inducing magnetic transitions from the paramagnetism of parent oxides to the antiferromagnetism of oxyhydride. The low dimension behaviors would been expected because of the nonbonding nature between the V t_2g and H s orbitals due to symmetry. Moreover, our results indicate that the direct hoppings of the nearest neighboring two V t_2g orbitals and the indirect hoppings mediated by Sr ions should be essential to understanding the electronic and magnetic properties of the perovskite oxyhydride.