PREPARATION OF (LA1-XSRX)2MNO4 WITH THE K2NIF4 STRUCTURE AND ITS ELECTRICAL-PROPERTIES

This work was done in order to prepare (La1-xSrx)2MnO4 (0.35 less-than-or-equal-to x less-than-or-equal-to 0.65) with K2NiF4 structure and to investigate their electrical properties. The La-rich (La1-xSrx)2MnO4 has been successfully prepared by a solid-state reaction method in vacuum. The lattice parameters of (La0.5Sr0.5)2MnO4 were the same as those of La2CuO4. This indicates that the Mn-O bond shrank in the a-b plane and the lattice expanded along the c-axis in the K2NiF4 structure by the co-operative Jahn-Teller effect. However, the lattice parameters increased along the a-axis and decreased along the c-axis as x deviates from x=0.5. This tendency differs from that of the (La1-xSrx)2CuO4 superconductor. The temperature dependence of electrical resistivity of (La1-xSrx)2MnO4 obeyed the Arrhenius law. The result showed that (La1-xSrx)2MnO4 (0.35 less-than-or-equal-to x less-than-or-equal-to 0.65) is a semiconductor.