Influence of K doping on the properties of perovskite molybdates Ba1 − xKxMoO3 (0 ≤ x ≤ 0.2)

The effect of K doping on structural, electronic transport, magnetic and specific heat properties in 4d perovskites Ba1 − xKxMoO3 (0 ≤ x ≤ 0.2) has been investigated. Partial substitution of K+ ions for Ba2+ ions does not change the space group, but decreases the lattice parameter a monotonously. All samples exhibit metallic behavior in the whole measured temperature range. The K doping does not change the Pauli-paramagnetic behavior in high temperature region, but a weak ferromagnetic (FM) transition is induced at about 50 K, which can be related to the deficiency of Mo. With K-doping content increasing, the resistivity increases, while the magnetic susceptibility and electronic specific heat coefficient decrease. The results are discussed according to the electron localization due to the disorder effect induced by dopants and the decrease in the density of state (DOS) at Fermi surface.