Author/Authors :
Yuan، نويسنده , , S.L and Peng، نويسنده , , G and Xia، نويسنده , , Z.C. and Liu، نويسنده , , J and Liu، نويسنده , , S and Li، نويسنده , , Z.Y. and Yang، نويسنده , , Y.P. and Liu، نويسنده , , L and Tang، نويسنده , , J and Zhang، نويسنده , , G.H. and Zhang، نويسنده , , L.J. and Feng، نويسنده , , W and Xiong، نويسنده , , C.S and Xiong، نويسنده , , Y.H، نويسنده ,
Abstract :
Based on investigations of metal–insulator transition temperature Tm on La2/3(Ca1−x′Srx′−x″Bax″)1/3MnO3, we point out that considerations based only on the mismatch effect or the strain-field effect cannot provide a reasonable description for the experimental observations. Including two contributions arising from the average A-cation size (〈rA〉) and the strain-field effect defined by a quantity S=〈(rA0−rA)2〉 gives Tm varying as Tm=Tm(〈rA〉,0)−pS, where Tm(〈rA〉,0) is the transition temperature in the absence of the strain-field effect and the parameter p is estimated to be ∼1.05×106 K nm−2. It is shown that the strain-corrected Tm shows a behavior expected by the double-exchange mechanism which monotonously increases towards ∼500 K with increasing 〈rA〉 towards rA0 (the A-cation size of an ideal cubic perovskite).
