On the optical and magnetic studies of YCrO3 perovskites
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2018
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In this paper we studied the Electron Paramagnetic Resonance (EPR) and Optical spectroscopies of mono disperse yttrium chromite (YCrO3) nanoparticles prepared by a modified polymeric precursor method. The particles
crystallized in roughly spherical shape with size ranging from 100 to 200 nm. Diffuse reflectance spectrum
exhibited very well defined bands related to the 4A2 → 4T2, 4A2 → 4T1, 4A2 → 2T1, 4A2 → 2
E transitions,
characteristic of Cr3+ (3d3, 2D5/2) ions in nearly octahedral symmetry. The crystalline field Dq, Racah para meters (B and C) and Dq/B, could be determined and the results indicated that Cr3+ ions are in a strong ligand
field site. The EPR spectra of YCrO3 shows a single broad resonance in the whole range of temperature studied,
100–300 K. Combining optical and EPR results the effective g-values of the paramagnetic Cr3+ were estimated to
be 1.97 and 1.98, respectively, typical of Cr3+ in orthorhombic crystal field environment. The onset of the
antiferro-paramagnetic transition, TÑ140 K, attributed to Cr3+-Cr3+ exchange interaction (J = −41.5 cm−1)
was determinate by means of Magnetization and EPR measurements. The results were discussed in terms of the
magnetic short-rang spin-spin exchange interaction between pairs of Cr3+.
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YCrO3, Orthochromite, Modified polymeric precursor method, EPR, Magnetic transition
Citação
JARA, Antonio N. L.; CARVALHO, Jesiel F.; FRANCO JÚNIOR, Adolfo; MAIA, Lauro J. Q.; SANTANA, Ricardo C. On the optical and magnetic studies of YCrO 3 perovskites. Physica B: condensed matter, Amsterdam, v. 546, p. 67-72, 2018. DOI: 10.1016/j.physb.2018.07.026. Disponível em: https://www.sciencedirect.com/science/article/pii/S0921452618304745. Acesso em: 25 maio 2023.