Neutron powder diffraction analysis of (Tm{sub 0.50}Ca{sub 0.50})MnO{sub 3} and (Lu{sub 0.50}Ca{sub 0.50})MnO{sub 3}

Journal Article · Sat Dec 15 04:00:00 EST 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.06.037· OSTI ID:22149948

Ferretti, M. ^[1]; Cimberle, M. R. ^[2]; Ritter, C. ^[3]

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1. SPIN-CNR, C.so Perrone 24, 16152 Genova (Italy)
2. IMEM-CNR, Via Dodecaneso 33, 16146, Genova (Italy)
3. Institute Laue-Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)

The crystal and magnetic structures of (Tm{sub 0.50}Ca{sub 0.50})MnO{sub 3} and (Lu{sub 0.50}Ca{sub 0.50})MnO{sub 3} have been investigated between 5 K and 300 K by means of high resolution neutron powder diffraction followed by Rietveld refinement and dc magnetic measurements. During cooling orbital ordering at the Mn sub-lattice takes place at T{sub OO}{approx}280 K in both compounds, inducing an orthorhombic to monoclinic phase transition. As the temperature is further decreased an antiferromagnetic CE-type structure occurs in both compounds at T{sub N}{approx}105 K. The comparison with other (Ln{sub 0.50}Ca{sub 0.50})MnO{sub 3} compounds reveals that at room temperature the average Jahn-Teller distortion increases sharply with the decrease of the ionic radius for lanthanides heavier than Sm. The ordered magnetic moment progressively decreases as the lanthanide ionic radius decreases on account of the decreased values of the Mn-O-Mn bond angles. - Graphical abstract: Rietveld refinement plot for (Tm{sub 0.50}Ca{sub 0.50})MnO{sub 3} obtained from neutron powder diffraction data collected at 5 K; the inset shows the CE-type spin ordering taking place at the Mn sub-lattice. Highlights: Black-Right-Pointing-Pointer The crystal and magnetic structures of (Tm{sub 0.50}Ca{sub 0.50})MnO{sub 3} and (Lu{sub 0.50}Ca{sub 0.50})MnO{sub 3} were analyzed by neutron powder diffraction. Black-Right-Pointing-Pointer Orbital ordering takes place below T{sub OO}{approx}280 K in both compounds. Black-Right-Pointing-Pointer An antiferromagnetic CE-type structure occurs in both compounds below T{sub N}{approx}105 K. Black-Right-Pointing-Pointer A Comparison with other (Ln{sub 0.50}Ca{sub 0.50})MnO{sub 3} compounds is reported.

• OSTI ID: 22149948
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 196; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ANTIFERROMAGNETISM
BOND ANGLE
COMPARATIVE EVALUATIONS
CRYSTALS
JAHN-TELLER EFFECT
MAGNETIC MOMENTS
MONOCLINIC LATTICES
NEUTRON DIFFRACTION
ORTHORHOMBIC LATTICES
PHASE TRANSFORMATIONS
RARE EARTHS
SPIN