Strontium Vanadium Oxide–Hydrides: “Square‐Planar” Two‐Electron Phases

Abstract

Abstract A series of strontium vanadium oxide–hydride phases prepared by utilizing a low‐temperature synthesis strategy in which oxide ions in Sr n +1 V n O 3 n +1 ( n =∞, 1, 2) phases are topochemically replaced by hydride ions to form SrVO 2 H, Sr 2 VO 3 H, and Sr 3 V 2 O 5 H 2 , respectively. These new phases contain sheets or chains of apex‐linked V 3+ O 4 squares stacked with SrH layers/chains, such that the n =∞ member, SrVO 2 H, can be considered to be analogous to “infinite‐layer” phases, such as Sr 1− x Ca x CuO 2 (the parent phase of the high‐T c cuprate superconductors), but with a d 2 electron count. All three oxide–hydride phases exhibit strong antiferromagnetic coupling, with SrVO 2 H exhibiting an antiferromagnetic ordering temperature, T N >300 K. The strong antiferromagnetic couplings are surprising given they appear to arise from π‐type magnetic exchange.