Hydrothermal synthesis and magnetic properties of RMn{sub 2}O{sub 5} (R=La, Pr, Nd, Tb, Bi) and LaMn{sub 2}O{sub 5+} {sub {delta}}

Journal Article · Sun Apr 15 04:00:00 EDT 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.02.005· OSTI ID:21015782

Yan, Chen ^[1]; Hongming, Yuan ^[1]; Ge, Tian ^[1]; Ganghua, Zhang ^[1]

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1. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130023 (China)

RMn{sub 2}O{sub 5} (R=La, Pr, Nd, Tb, Bi) crystallites were prepared by a mild hydrothermal method and characterized by powder X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS) and magnetic measurement. The formation of manganates was sensitive to the alkalinities and Mn-containing precursors of the reaction mixtures. This family of manganates is isostructural and has a space group of Pbam. The magnetic measurements for RMn{sub 2}O{sub 5} showed an antiferromagnetic transition. The strong irreversibility between the ZFC and FC curves indicated a helicoidally magnetic structure below 40 K. The max d.c. susceptibilities of LaMn{sub 2}O{sub 5+} {sub {delta}} ({delta}=0.01, 0.06, 0.08, 0.16, 0.17) were found to be variable and the excess oxygen ({delta}) in the compounds was influenced by the alkalinity used in the hydrothermal synthesis. - Graphical abstract: Several RMn{sub 2}O{sub 5} (R=La, Pr, Nd, Tb, Bi) and LaMn{sub 2}O{sub 5+} {sub {delta}} crystallites were prepared by the mild hydrothermal treatment of mixtures of rare-earth oxides, K-birnessite gel and KOH. The magnetic susceptibility measurements show an antiferromagnetic transition in RMn{sub 2}O{sub 5} (R=Pr, Nd, Bi). Magnetic susceptibility of the LaMn{sub 2}O{sub 5+} {sub {delta}} was variable at low temperature due to the different oxygen excess in the compound, which is dominated by the different KOH concentration used in the hydrothermal synthesis.

• OSTI ID: 21015782
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 4 Vol. 180; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ACID NEUTRALIZING CAPACITY
ANTIFERROMAGNETISM
GELS
HYDROTHERMAL SYNTHESIS
MAGNETIC SUSCEPTIBILITY
MANGANATES
OXIDES
POTASSIUM HYDROXIDES
RARE EARTH COMPOUNDS
SCANNING ELECTRON MICROSCOPY
SPACE GROUPS
TEMPERATURE RANGE 0013-0065 K
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY