Low temperature preparation and characterization of In1−xLnxBO3 (x = 0.0 and 0.05; Ln = Gd, Eu, Dy and Sm): ESR of In0.95Gd0.05BO3 and emission of In0.95Eu0.05BO3

Indium borate and rare earth substituted indium borates (In1−xLnxBO3 (x = 0.0 and 0.05; Ln = Gd, Eu, Dy and Sm)) are prepared at low temperature by metathesis reaction using InCl3, LnCl3 and NaBO2. They are characterized by powder XRD and infrared spectroscopy. All the compositions (In1−xLnxBO3) crystallize in hexagonal lattice with calcite structure. These borates gave characteristic IR vibrations of planar BO3 group. Spin-Hamiltonian parameters for Gd3+ are deduced from room temperature electron spin resonance spectrum of In0.95Gd0.05BO3. The electron spin resonance spectrum of In0.95Gd0.05BO3 gave several anisotropic lines with g > 2.0. The ESR spectrum of the sample belongs to the “intermediate” category with 1/4 < HCF/hν < 1. The local symmetry of Eu3+ in In0.95Eu0.05BO3 is obtained from its emission spectrum. The R/O ratio of In0.95Eu0.05BO3 suggests the occupation of In3+ site by Eu3+ with near symmetric octahedral geometry.