Properties of Ru-Doped Ca-Pr Manganate Thin Films Fabricated by PLD Technique

The Ca_0.85Pr_0.15Mn_1-yRu_yO₃ (y = 0, 0.04, 0.08, 0.12, 0.16, and 0.20) manganate thin films were prepared by pulsed laser deposition (PLD) technique. The X-ray diffraction (XRD) analysis revealed that the samples were single-phased with orthorhombic structure. The scanning electron microscopy (SEM) images indicated that the samples were composed of homogeneous grains. The Hall-effect measurements showed that the carrier density and Hall mobility of films increased with increasing Ru-doped content. The magnetic field dependence of magnetization at various temperatures were measured by using the superconducting quantum interference device (SQUID) and showed that the increase of Ru-doping content induced the large ΔS change in broad range of temperature. This demonstrates a possible application of these materials in cooling devices as the relative cooling power (RCP) is proportial to -(ΔS)_maxΔ_TFWHM (where Δ_TFWHM is the full width at half-maximum of ΔS).