Growth and characterization of Pt-protected Gd₅Si₄ thin films

Successful growth and characterization of thin films of giant magnetocaloric Gd₅(Si_xGe_1−x)₄ were reported in the literature with limited success. The inherent difficulty in producing this complex material makes it difficult to characterize all the phases present in the thin films of this material. Therefore, thin film of binary compound of Gd₅Si₄ was deposited by pulsed laser deposition. It was then covered with platinum on the top of the film to protect against any oxidation when the film was exposed to ambient conditions. The average film thickness was measured to be approximately 350 nm using a scanning electron microscopy, and the composition of the film was analyzed using energy dispersive spectroscopy. X-ray diffraction analysis indicates the presence of Gd₅Si₄ orthorhombic structure along with Gd₅Si₃ secondary phase. The transition temperature of the film was determined from magnetic moment vs. temperature measurement. The transition temperature was between 320 and 345 K which is close to the transition temperature of the bulk material. Magnetic moment vs. magnetic field measurement confirmed that the film was ferromagnetic below 342 K.