title: Microwave-assisted synthesis, microstructure, and physical properties of rare-earth chromites.
abstract: The full rare-earth (RE) chromites series (RE)CrO(3) with an orthorhombic distorted (Pnma) perovskite structure and the isostructural compound YCrO(3) can be synthesized through a simple microwave-assisted technique, yielding high-quality materials. Magnetization measurements evidence that the Néel temperature for antiferromagnetic Cr(3+)-Cr(3+) ordering strongly depends on the RE(3+) ionic radius (IOR), and a rich variety of different magnetic spin interactions exists. Dielectric spectroscopy on sintered pellets indicates electronic inhomogeneity in all samples as manifested by the presence of at least two dielectric relaxation processes associated with grain boundary and grain interior bulk contributions. X-ray diffraction, Raman spectroscopy, and temperature-dependent dielectric permittivity data do not indicate potential noncentrosymmetry in the crystal or concomitant ferroelectricity. Strong correlations between the magnetic and dielectric properties were not encountered, and microwave-synthesized (RE)CrO(3) may not be classified as magnetoelectric or multiferroic materials.
authors.affiliation: Departamento Química Inorgánica, Facultad de CC. Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Prado-Gonjal
authors.forename: Rainer
authors.initials: R
authors.lastname: Schmidt
authors.forename: Juan-José
authors.initials: JJ
authors.lastname: Romero
authors.forename: David
authors.initials: D
authors.lastname: Avila
authors.forename: Ulises
authors.initials: U
authors.lastname: Amador
authors.forename: Emilio
authors.initials: E
authors.lastname: Morán
mesh_terms: D002857:Chromium / Q000737:chemistry*; D008872:Microwaves; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D015019:Yttrium / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D002857:Chromium; D015019:Yttrium