Effect of Mn doping on the structural, magnetic and transport properties of SiC films

• The structural, magnetic and transport properties of films was investigated.
• Majority of Mn atoms form the Mn4Si7 secondary phase compounds.
• The carbon-incorporated Mn4Si7 compounds are the origin of ferromagnetism.

Mn-doped SiC films were deposited on Si (1 0 0) substrates by the radio frequency (RF) magnetron sputtering technique. The effect of Mn doping on the structural, magnetic and transport properties of films was systematically investigated. The results show that the Mn-doped SiC films have a 3C-SiC crystal structure and majority of Mn atoms form the Mn4Si7 secondary phase compounds. The carrier concentration increases and resistivity decreases monotonically with the increase of Mn concentration. A crossover from semiconducting to metallic transport behavior is observed and the metal–semiconductor transition temperature decreases as the Mn concentration increases. Magnetic characterizations show that all films are ferromagnetic with a Curie temperature (TC) of above 300 K, and the saturated magnetization (Ms) increases monotonically with the increase of Mn concentration. The carbon-incorporated Mn4Si7 compounds can be considered the origin of the observed ferromagnetism in Mn-doped SiC films.