Infrared and Raman Study of (La1-xSrx)2NiO4 and La2(Ni1-xCux)O4 Motivated by the observation of the close correlation between disappearance of the infrared absorption peak at about 680 cm -1 and the appearance of high- T c superconductivity in (La 1- x M x ) 2 CuO 4 (M=Ca, ...
The electrical conductivity of (La1‐xSrx)2NiO4‐δ ceramics at 500‐1000°C and p(O2) ≥ 10‐3 atm is p‐type metallic‐like. The highest conductivity, 300 S/cm at 800°C in air, is observed for x = 0.6. The average thermal expansion coefficients, (14.0‐15.4)×10‐6 K‐1 ...
A broad peak was observed in susceptibility at about 650K for x= 0.50, as reported for superconductive oxides (La1-xSrx)2CuO4 (LSCO). The broad peak is attributed to the two-dimensional antiferromagnetic (2DAF) correlation among Ni3+ spins with S=l/2. However, contrary to LSCO, the ...
LA2NIO4LA2-XSRXNIO4ONSETANTIFERROMAGNETISMWe report measurements of the electrical resistivity, the Seebeck-coefficient and the magnetic susceptibility of samples (La 1− x Sr x ) 2 NiO 4+δ in the concentration range 0 ≤χ≤ 0.5. All compounds exhibit semiconducting behaviour at low ...