Anhydrous oxygen-free rare earth material preparation and characterization. (December 2021)

• Record Type: Journal Article
• Authors: Hung, N.T.; Thuy, N.T.; Thuan, L.B.; Tra, D.T.T.; Van Khoai, D.; Jeon, J.H.; Lee, J.-Y.; Jyothi, R.K.
• Is Part Of: Materials today chemistry. Volume 22(2021)
• Publication Date: 2021-12
• Subjects: Anhydrous terbium (and dysprosium) fluoride -- Ammonium bifluoride -- Fluorination -- Calcinothermic reduction; Chemistry -- Periodicals; Materials -- Research -- Periodicals; Materials science -- Periodicals; Chemistry; Materials -- Research; Electronic journals; Periodicals; 660.282
• DOI: 10.1016/j.mtchem.2021.100608
• Languages: English
• ISSNs: 2468-5194

Abstract

Abstract: The present paper addresses the preparation and characterization of anhydrous oxygen-free rare earth materials, such as terbium fluoride (TbF3 ). The fluorination of terbium oxide (Tb4 O7 ) by ammonium bifluoride (NH4 HF2 ) to prepare anhydrous TbF3 was reported in this work. The parameters affecting fluorination were studied, including the fluorination temperature, excess stoichiometric amount of NH4 HF2, and time for fluorination. The temperatures of Tb4 O7 fluorination by NH4 HF2 determined by thermogravimetric analysis and differential thermal analysis ranged from 350°C to 500°C. The phase structure of the as-prepared products identified by the X-ray diffraction method was indexed to the orthorhombic phase of TbF3 [space group: Pnma (no. 62)] that exhibited good accordance with the values in the standard cards JCPDS No. 37-1487 for TbF3 . Energy-dispersive X-ray spectroscopy (EDS) methods were used to analyze the elemental compositions in the as-prepared products; the fluorine (F) and terbium (Tb) elemental compositions calculated from the [TbF3 ] formula are in good agreement with those calculated from the EDS pattern. The optimum parameters for fluorination were determined from the results, and anhydrous oxygen-free TbF3 can be used to study the preparation of metallic terbium by the calcinothermic reduction method. Graphical abstract: Experimental set-up for the fluorination of terbium oxide by ammonium bifluoride. Image 1 Highlights: The preparation of the anhydrous terbium fluoride was reported in the work. Experimental parameters are optimized, those are affecting on the fluorination. The XRD and EDS methods were used to identify the phase and element compositions. The anhydrous terbium fluoride is oxygen-free. The product is used to study on preparation of metallic terbium.