Mv. Lobanov et al., Structural and magnetic properties of the colossal magnetoresistance perovskite La0.85Ca0.15MnO3, PHYS REV B, 61(13), 2000, pp. 8941-8949
A single phase sample of La0.85Ca0.15MnO3 with uniform cation distribution
and complete oxygen stoichiometry was synthesized by freeze-drying techniqu
e and studied by a variety of methods. The sample is ferromagnetic below T-
C= 170 K with mu(Mn)= 2.9(1) mu(B) at 10 K. Precise examination of the crys
tal structure by a combination of electron diffraction, high-resolution ele
ctron microscopy, and neutron powder diffraction revealed a monoclinic dist
ortion of the GdFeO3-type structure [S.G. P2(1)/c, a=7.74476(6) Angstrom, b
=5.50398(4) Angstrom, c = 5.47351(4) Angstrom, beta= 90.091(2)(0)] with no
nequivalent MnO2 layers alternating along the a axis. The crystal structure
is characterized by a specific pattern of Mn-O distances implying an uncon
ventional orbital ordering type. A possible relation to charge ordering is
described within the bond valence sum framework.