Spectroscopic and Morphological Examination of Co0.9R0.1MoO4 (R = Ho, Yb, Gd) Obtained by Glycine Nitrate Procedure

The glycine nitrate procedure (GNP) is a method that proved to be the easiest and most effective method for controlling the composition and morphology during the synthesis of Co_0.9R_0.1MoO₄ (R = Ho, Yb, Gd). This method of the combustion process achieves control of stoichiometry, homogeneity, and purity. Metal nitrates and glycine were mixed in the appropriate stoichiometric ratios to produce Co_0.9R_0.1MoO₄ (R = Ho, Yb, Gd). The samples obtained by the mentioned method were further subjected to different characterization methods such as differential thermal analyses (DTA), X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), spectroscopy, field emission scanning electron microscopy (FESEM), and nitrogen adsorption method. A high level of anisotropy of the shape and size of particles in the form of agglomerates was found. Also, there are noticeable differences in the microstructure and plate crystals. The color of the synthesized sample changes from darker to lighter shades after thermal treatments. There are pronounced changes in the dominant wavelength (nm) and color purity between the initial sample and the sample after heating (1100 °C) due to the concentration of Co.