Magnetocaloric effect and temperature coefficient of resistance of La _0.85Ag_0.15MnO₃ epitaxial thin films obtained by polymer-assisted deposition

We report the magnetocaloric effects and temperature coefficient of resistance (TCR) of La_0.85Ag_0.15MnO₃ epitaxial thin films grown on single-crystal substrates of LaAlO₃ (001) and SrTiO₃ (001) using the chemical solution approach of polymer-assisted deposition (PAD). The film thicknesses are in the range 30-35 nm. Magnetocaloric effects, with entropy changes of -2.14 J/kg.K, in the case of the LaAlO₃ substrate and -2.72 J/kg.K for the SrTiO₃ substrate, (corresponding to a magnetic field variation of 2T) were obtained at room temperature. The refrigeration capacity at this field variation reached large values of 125 J/kg and 216 J/kg, indicating that these films prepared by PAD have the potential for microcooling applications. The temperature coefficient of resistance has been calculated from the resistivity measurements. A maximum TCR value of 3.01 % K^-1 was obtained at 309 K, which shows that these films also have potential as uncooled thermometers for bolometric applications.