Spin-orbit coupling controlled ground states in the double perovskite iridates A2BIrO6 (A= Ba, Sr; B= Lu, Sc)

Iridates with the 5d4 electronic configuration have attracted recent interest due to reports of magnetically ordered ground states despite longstanding expectations that their strong spin-orbit coupling would generate a J=0 electronic ground state for each Ir5+ ion. The major focus of prior research has been on the double perovskite iridates Ba2YIrO6 and Sr2YIrO6, where the nature of the ground states (i.e., ordered vs nonmagnetic) is still …