XAS Study of LaMn1xGaxO3 Series

Persistence of Jahn-Teller Distortion up to the Insulator to Metal Transition inLaMnO3

“…M. Baldini, 1, 2 V. V. Struzhkin, 3 A. F. Goncharov, 3 P. Postorino, 4,5 and W. L. Mao 1,2,6 LaMnO 3 is the parent compound for many doped manganites which exhibit colossal magnetoresistance (CMR). This system displays a complex correlation between structural, orbital, magnetic, and electronic degrees of freedom.…”

“…It has an orthorhombic Pmna structure and transforms into an antiferromagnetic (A-type) insulator at T N =140 K [2]. At T JT =750 K, LaMnO 3 changes from a static orbital ordered state with cooperative JT distortion to an orbital disordered state with dynamic, locally JT distorted octahedra [3]. This order-disorder transition is also accompanied by an abrupt decrease in the electrical resistivity.…”

“…P-T evolution of TN (white squares) [32]. The star and the black square indicate the JT transition and the IMT temperatures respectively [3,4]. Dark grey area indicates the insulating P-T region.…”