FeSe film was prepared on GaAs (001) substrate by low pressure metal-organic chemical vapor deposition. The x-ray diffraction measurement indicated that the sample was preferentially oriented with tetragonal structure. The structure relationship between FeSe epilayer and GaAs (001) substrate has been studied. The critical behavior in the temperature-dependent resistivity at ∼290K is close to the Curie temperature, which confirmed that the transformation from ferromagnetism to paramagnetism could be responsible for the critical behavior.

FeSe films have been grown on GaAs (001) substrates by low-pressure metal organic vapor deposition at different temperatures. X-ray diffraction analysis indicated that the FeSe films grown at substrate temperatures (Ts) between 220 and 340°C were preferentially oriented with tetragonal structure. It was not possible to deposit films at Ts above 400°C. The atomic molar ratios of Se∕Fe increased with increasing the flow rate of H2Se∕Fe(CO)5 and the growth temperature. The electronic property results showed that the conductive type of FeSe could be adjusted by controlling the growth temperature. The coercivity of FeSe decreased with increasing the growth temperature from 220to300°C due to the improvement of crystal quality.