Controlled synthesis processes of cobalt containing borates in a multi-component flux system based on Bi 2 O 3 –MoO 3 –Na 2 O–B 2 O 3

Targeted Ni 2+ doping shifts the Co 3− x Ni x B 2 O 6 –Co 3− x Ni x BO 5 phase boundary and enables reversible switching at Co 3 B 2 O 6 –Co 3− x Ni x BO 5 –Ni 3 B 2 O 6 triple point at x = 1. The precise synthesis control and redox management in cobalt materials are demonstrated.