Effect of Co Doping on the Structure and Magnetic Properties of TmMn1-xCoxO3

We report the structure and magnetic properties of Co-doped TmMnO3 polycrystals for Co doping levels of 0 ≤ x ≤ 0.9. TmMnO3 (x = 0) prepared at ambient pressure was hexagonal. Hexagonal and orthorhombic phases coexisted in TmMn1−xCoxO3 for 0 ≤ x < 0.5. We obtained almost single-phase orthorhombic samples with 0.5 ≤ x ≤ 0.9 using complex polymerization. Ferromagnetic orthorhombic TmMn1−xCoxO3 formed upon Co doping. The ionic states of Tm, Mn, and Co were determined through magnetization measurements. The rapid decrease in magnetization for 0.5 ≤ x ≤ 0.7 below about 25 K was explained using a model consisting of a combination of ferromagnetic Mn–Co and paramagnetic Tm sublattices

Effect of Oxygen Pressure on Thermoelectric Properties of p-Type CuAlO2 Films Fabricated by Pulsed Laser Deposition

We focus on the growth of p-type CuAlO2 thin films and its thermoelectric properties. Thin films are deposited by pulsed laser deposition technique on single-crystal sapphire substrates varying the oxygen partial pressure. Thin film deposited at oxygen partial pressure of 200 mTorr presents bigger grains (about 10 μm in size) and shows Seebeck coefficient as high as 270 µV/K with a conductivity of about 0.8 S/cm so that its power factor is about 5.7 µW/mK2 at 800 K, twice than observed in the film deposited at 60 mTorr of oxygen