“…The oxidation state of palladium in these compounds strongly depends on the synthesis technique. While compounds of divalent palladium, such as Ba 2 PdO 3 [1], MPd 3 O 4 (MQCa, Sr, Cd) [2,3] and Lu 0.5 Na 0.5 Pd 3 O 4 [4] have been prepared by a conventional solid-state reaction or hydroxide flux method, a high-pressure technique was applied to synthesize complex oxides containing Pd in higher oxidation states, such as LnPd 2 O 4 (LnQLa, Pr, Nd, Gd, Y) [5], LaPdO 3 [6], Zn 2 PdO 4 [7] and M 4 PdO 6 (MQCa, Sr) [8].…”