Disorder–order structural transition in amorphous LaSrMnO films

Using the x-ray diffraction method, the atomic rearrangement in amorphous La0.6Sr0.2Mn1.2O3 films is investigated at growth temperatures Ts = 20-300 deg C. Two stages in the disorder-order phase transition are discovered. In the first stage, amorphous structure undergoes ordering at Ts = 100 deg C up to a maximal concentration of small (D30 A) clusters which occupy 90% of the total volume. In the Ts = 100-150 deg C temperature interval, disordering in the structure and a change in short-range order prepare the onset of a second stage. In the second stage, starting with Ts = 150 deg C, the progressive crystallization and transition from mesoscale order to long-range atomic order at Ts = 300 deg C take place. It is shown that all transitions produce changes in the conductivity mechanisms and magnetic properties of the films.