Solid‐State Reactivity of the ZnO‐xMn₂O₃System During Heat Treatment

Abstract

Using X‐ray, infrared, and electron paramagnetic resonance methods, the reactivity of ZnO+xMn2O3 systems during heat treatment was studied. Results showed that the solubility of manganese (Mn) in zinc oxide (ZnO) is lower than 3% and that reaction diffusion occurs. Reaction processes that take place in this system promote disintegration of Mn2O3 particles into microfragments and causes them to move along the surface of the ZnO particles (solid‐state reactive wetting process).

Structural, chemical and magnetic investigations of polycrystalline Zn1−xMnxO

“…All these reports are on different forms of this compound viz. polycrystalline bulk, epitaxial thin films or nanostructures [7][8][9][10][11][12][13][14][15][16][17][18]. Albeit the large number of reports on this system, the results are either inconclusive or contradictory and lack reproducibility.…”

EPR detection of sphalerite ZnO in mechanically treated ZnO+0.1C nanosystem

“…The EPR spectra of Mn 2 þ ions in two different ZnO environments are also shown in Fig. 2: (b) МP treated samples of ZnOþ1.0% MnO 2 [26,27]; and (c) sintered samples of ZnO þ0.1% MnO 2 [33]. In the case of (c) well-resolved hyperfine and fine structures of Mn 2 þ EPR-spectrum were observed, which is typical for flawless polycrystalline ZnO Wt samples.…”

“…Note that information related to the preparation of the samples (ZnO, ZnO with additives of SnO 2 , TiO 2 , MnO 2 , NiO, Gd 2 O 3 ), and the study of the formation and evolution of different paramagnetic centers during Mechanical Processing have been previously described for our group [26,27,33,[43][44][45][46][47]. The formation of different paramagnetic states during MP of ZnO þC mixtures had been described in [48].…”

“…(a) ZnO Wt þ 0.1% C sample after t MP ¼ 390 min of MP (upper inset shows the position of central transitions for spectrum S(II)), this study; (b) ZnO þ1.0% MnO 2 sample after t MP ¼ 180 min of MP (upper inset shows the position of central transitions for sextet S(II); lower inset shows the position of central transitions for sextet S(I)) [26,27]; (c) ZnO þ0.1% MnO 2 sample sintered at 1000°C (upper inset shows the position of central transitions in the EPR spectrum of Mn 2 þ ions for sextet S(II); lower inset shows the position of singularities of the central transitions Mn 2 þ: ZnO Wt for θ 1 ¼ 90°and θ 2 E 57°in the spectrum of polycrystalline samples)[33].…”

Kinetics of physico-chemical processes during intensive mechanical processing of ZnO–MnO2 powder mixture

“…But Driessens and Rieck have shown that Mn solubility in ZnO is lower, less than 2% in the 873-1723 K temperature interval [28]. Kakazey et al [29] Contents lists available at ScienceDirect also reported solubility lower than 3%. The formation of the solid solution ZnO:Mn 2 þ during prolonged mechanical processing (MP) of powder mixtures of ZnOþ 1%wt MnO 2 and ZnO þ10%wt MnO 2 were observed by electron paramagnetic resonance spectra by Kakazey et al [25,26].…”