Spin state of cobalt ion in Nd(Cr{sub 1-x}Co{sub x})O{sub 3}

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1996.0116· OSTI ID:269881

Taguchi, Hideki ^[1]

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1. Okayama Univ. (Japan)

Perovskite-type Nd(Cr{sub 1-x}Co{sub x})O{sub 3} was synthesized in the range O {le} x {le} 1.0, and has the orthorhombic GdFeO{sub 3}-type structure with space group Pnma. The decrease of the average (Cr, Co)-O distance and the effective magnetic moment ({mu}{sub eff}) indicate that the Co{sup 3+} ion in Nd(Cr{sub 1-x}Co{sub x})O{sub 3} is in the low-spin state (d{epsilon}){sup 6}(d{gamma}){sup O} at low temperature. With increasing temperature, the 1/{chi}{sup -T} curve exhibits the plateau, and this plateau indicates the temperature interval where there is a conversion from the low-spin state of the Co{sup 3+} ion to a mixed spin state. From the results of the electrical resistivity ({rho}), Nd(Cr{sub 1-x}Co{sub x})O{sub 3} is semiconductive with the energy gap (E{sub g}) of {approx} 0.36-0.47 eV. The log {rho}-1000/T curves at high temperature deviate from those at low temperature. Rietveld analysis indicates that each (Cr, Co)O{sub 6} octahedron has little distortion and that the average angles for (Cr, Co)-O(1 and 2)-(Cr, Co) increase with increasing x, in agreement with the decrease in the average (Cr, Co)-O distance. Therefore, it is apparent that the magnetic and electrical properties of Nd(Cr{sub 1-x}Co{sub x})O{sub 3} depend on the spin state of the Co{sup 3+} ion and a cation-anion-cation overlap.

• OSTI ID: 269881
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 122; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHROMIUM
CHROMIUM OXIDES
COBALT OXIDES
ELECTRIC CONDUCTIVITY
IONS
MAGNETIC MOMENTS
NEODYMIUM OXIDES
ORTHORHOMBIC LATTICES
PHYSICAL PROPERTIES
SPIN
STOICHIOMETRY