We studied the crystal and magnetic structure of the La14Ca34MnO3 compound using ultrahigh resolution synchrotron x-ray and neutron-diffraction techniques. The experimental results revealed that the particular compound undergoes a structural transition at TCO=220K. This transition results in an increase of the orthorhombic splitting and the appearance of superlattice diffraction peaks, which can be indexed assuming a supercell 4a (a is the unit cell parameter for T>TCO). This transition is reminiscent of those observed for the x=12 and x=23 stoichiometries where superstructures with 2a and 3a, respectively, have been observed. At TN=160K the neutron-diffraction patterns exhibit additional diffraction peaks, corresponding to antiferromagnetic long-range order with propagation vectors k=[14,0,12] and k=[12,0,12]. In addition to the structural transition at TCO the synchrotron high resolution x-ray diffraction patterns revealed a three phase coexistence.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2005 Aug 1|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics