Electrodes and their fabrication methods as well as applications

A method of fabricating an electrode, comprising steps of:

• providing a complex metal oxide target, wherein the complex metal oxide target is composed of manganese oxide, cobalt oxide and zinc oxide, and based on the overall complex metal oxide film, the amount of manganese element of manganese oxide ranges from 65 at % to 79.2 at %;
• the amount of cobalt element of cobalt oxide ranges from 10.4 at % to 17.5 at %;
• the amount of zinc element of zinc oxide ranges from 10.4 at % to 17.5 at %;
• providing a substrate;
• and
• heating the substrate to a heating temperature between 200° C. and 600° C.;
• applying a bias potential to the heated substrate;
• forming a complex metal oxide film on a surface of the substrate by radio frequency magnetron sputtering under a sputtering time, a sputtering power, a sputtering pressure and a volume flow rate of oxygen to obtain the electrode, wherein the substrate bias potential is between 0 V and −100 V.