Morphology,structure and magnetic behavior of orthorhombic and hexagonal HoFeO3 synthesized via solution combustion approach

• 作者: K.D.Martinson I.S.Kondrashkova M.I.Chebanenko A.S.Kiselev T.Yu Kiseleva V.I.Popkov
• 来源期刊: 稀土学报（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: MAGNETISM AND MAGNETIC MATERIALS
• 页码范围: 296-301
• 页数: 6页
• 语种: 英文

摘要

Nanostructured HoFeO3 powders were obtained by solution combustion method at various glycine-nitrate ratios (G/N =0.2,0.4… 1.4).According to X-ray powder diffractometry data,the presence of two modifications of HoFeO3 in the synthesized samples was established:orthorhombic (Pbnm) and hexagonal (P63/mmc).The crystallite size of the obtained compositions varies from 62 ± 6 to 29 ± 3 nm,depending on the G/N ratio.From magnetic structure studies,it is found that HoFeO3 obtained with a stoichiometric amount of glycine in the reaction solution is in the magnetically ordered state and is represented by a sextet with quadrupole splitting (QS) =0 mm/s,isomeric shift (IS) =0.36 mm/s and effective field strength (Heff) =497 kOe.According to the results of vibrational magnetometry,it is found that the orthoferrites obtained have a ferromagnetic structure,the main parameters of which (Ms,Mr and Hc) systematically change with a change in the redox ratio of the reaction mixture and,as a consequence,their phase composition,and reach maximum values at a G/N ratio =0.6.In the samples obtained with a significant excess and lack of glycine (G/N-0.2 and 1.4),despite their amorphous nature,hysteresis loops characteristic of the ferromagnetic state of the substance is observed.It is hopeful to obtain a pure hexagonal modification of HoFeO3 via heat treatment on amorphous products of glycine-nitrate combustion.