https://doi.org/10.1007/s100510170330
Evolution of (La1-yPry)0.7Ca0.3MnO3 crystal structure with A-cation size, temperature, and oxygen isotope substitution
1
Frank Laboratory of Neutron Physics, JINR, 141980, Dubna, Russia
2
Laboratory for Neutron Scattering ETHZ & PSI, 5232 Villigen PSI, Switzerland
3
RRC "Kurchatov Institute", Kurchatov sq. 1, 123182, Moscow, Russia
4
Chemistry Department, Moscow State University, 119899, Moscow, Russia
Corresponding author: a Denis.Sheptyakov@psi.ch
Received:
28
April
2000
Published online: 15 January 2001
The atomic structure of
compound with
has been systematically studied by neutron
powder diffraction in the temperature range from 15 to 293 K.
For composition with y=0.75, the structural analysis was
performed on two samples, one containing the natural mixture
of oxygen isotopes and the other one 75% enriched by
. The room temperature structural characteristics
of the series, including cell volume, average Mn-O
bond distance, and average Mn-O-Mn bond angle,
are the linear functions of the 
.
Temperature dependencies of these parameters are quite smooth,
except for the point 
, where a jump like changes
occur. The isotope enriched samples have been found identical
in crystal and magnetic structure down to the temperature of
transition of the sample with 
into the metallic
ferromagnetic phase. It confirms that different transport and
magnetic properties of the samples with and
at low temperature are driven by the different
oxygen atoms dynamics solely. Temperature dependencies of the
CO and AFM diffraction peak intensities and of the peak
widths for compositions close to the metal-insulator boundary
(
) indicate the macroscopically phase separated
AFM-dielectric + FM-metallic state below TFM.
PACS: 75.30.Vn – Colossal magnetoresistance / 61.12.Ld – Single-crystal and powder diffraction
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001
