This article is cited in 7 papers

CONDENSED MATTER

Phase transition in nanostructured LaMnO$_3$

M. V. Kharlamova^a, A. Arulraj<sup>b

a</sup> Faculty of Materials Science, MSU
^b Hahn-Meitner-Institut, Berlin, Germany

Abstract: Nanocrystalline LaMnO₃ samples have been synthesized by the coprecipitation of lanthanum and manganese salt solutions followed by annealing at 800°C in air and then in an argon flow. With the use of X-ray and neutron diffraction analysis, it has been found that the resulting samples had an orthorhombic crystal structure (space group Pbnm). In the nanocrystalline LaMnO₃ samples, an order-disorder phase transition from the low-temperature phase to the high-temperature phase occurs at (220 ± 10)°C, which is much lower than the value of 477°C for bulk LaMnO₃. The phase transition is due to the removal of the Jahn-Teller distortion of the Mn³⁺O₆ oxygen octahedrons and is accompanied by a decrease in the unit cell volume of lanthanum manganite over a narrow temperature range.

PACS: 64.70.Nd

Received: 05.11.2008
Revised: 16.02.2009

 English version: Journal of Experimental and Theoretical Physics Letters, 2009, 89:6, 301–305

Bibliographic databases:

• 
•