Electrical and Magnetic Properties of LnOZnPn (Ln: Rare Earths; Pn: P, As, Sb).

Abstract Electrical and magnetic properties of oxypnictides LnOZnPn (Ln = rare earths, Pn = pnictogen elements) with a ZrCuSiAs structure are investigated. The electrical resistivity of LnOZnPn decreases with an atomic number of Pn. The electrical resistivity has a maximum at Ln = Ce and then decreases with an atomic number of Ln in LnOZnAs, and it decreases with an atomic number of Ln in LnOZnSb. While LnOZnPn (Ln = La, Ce, Pr, Pn = P, As) are semiconducting, LnOZnSb (Ln = La, Ce) show a metal–semiconductor transition and NdOZnPn (Pn = As, Sb) become metallic. While LaOZnPn shows a diamagnetism, other LnOZnPn are paramagnetic. The effective magnetic moment μ eff deviates from the trivalent free ion values with an atomic number of Pn and Ln. The correlation between the deviation of μ eff and the decrease of the electrical resistivity suggests that 4f electrons contribute to the electrical conduction.