Spectroscopic, optical, magnetic and dielectric investigation of the orthoborate Ba2Co(BO3)2 nanopowder

Abstract

Nano-polycrystalline phase of Ba2Co(BO3)2, has been successfully obtained by the standard solid-state reaction. The Ba2Co(BO3)2 crystallizes in the monoclinic cell with the space group C2/m. The cell parameters are: a = 12.027 A, b = 5.340 A, c = 10.295 A, and β = 117.228°. The average grain size determined from Debye–Scherer’s equation is 40.29 nm. The surface morphology of the studied borate is consisting of the regular-shaped particles and the SEM reveals homogenous particles of nanotubes shapes. The elemental composition is confirmed by Energy Dispersive Spectrometry (EDS). The infrared and Raman studies confirm the existence of the BO3 groups. The calculated gap energy (E = 3.57 eV for the indirect mode and E = 3.9 eV for the direct one) is reported which is typical for wide-band-gap semiconductor materials. The magnetic measurements established that the predominant interactions in this borate are antiferromagnetic. The thermal investigation of the borate studied by the differential scanning calorimetry (DSC) highlights several anomalies, which could correspond either to phase transitions or to change in the physical behavior of the material. These phenomena are observed and interpreted by means of the dielectric study at high temperature.