Yun Han-Sol, Yun Byeong-Gyu, Shin So-Young, Jeong Dae-Yong, Cho Nam-Hee
Department of Materials Science and Engineering, Inha University, Nam-gu, Incheon 22212, Korea.
Nanomaterials (Basel). 2021 Mar 17;11(3):754. doi: 10.3390/nano11030754.
The crystallization kinetics in BaTiO synthesis from hydrate precursors via microwave-assisted heating (MWH) were investigated. The structural and chemical features of powders synthesized via MWH and conventional heating (CH) were compared. The charged radicals generated under microwave irradiation were identified by chemical analysis and real-time charge flux measurements. Using Ba(OH)∙HO (BH1), Ba(OH) (BH0), and BaCO (BC) as the precursors for a Ba source, and TiO∙4HO (TH) for a Ti source, three different mixture samples, BH1TH (BH1 + TH), BH0TH (BH0 + TH), and BCTH (BC + TH), were heat-treated in the temperature range of 100-900 °C. BaTiO powders were synthesized at temperatures as low as 100 °C when sample BH1TH was subjected to MWH. Based on the growth exponent (), the synthesis reactions were inferred to be diffusion-controlled processes (3 ≤ ≤ 4) for MWH and interface-controlled processes (2 ≤ ≤ 3) for CH. Current densities of approximately 0.073 and 0.022 mA/m were measured for samples BH1TH and BH0TH, respectively, indicating the generation of charged radicals by the interaction between the precursors and injected microwaves. The radicals were determined as OH groups by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.
研究了通过微波辅助加热（MWH）由水合物前驱体制备BaTiO时的结晶动力学。比较了通过MWH和传统加热（CH）合成的粉末的结构和化学特征。通过化学分析和实时电荷通量测量确定了微波辐照下产生的带电自由基。使用Ba(OH)∙HO（BH1）、Ba(OH)（BH0）和BaCO（BC）作为Ba源的前驱体，以及TiO∙4HO（TH）作为Ti源，对三种不同的混合样品BH1TH（BH1 + TH）、BH0TH（BH0 + TH）和BCTH（BC + TH）在100-900°C的温度范围内进行热处理。当样品BH1TH进行MWH时，在低至100°C的温度下合成了BaTiO粉末。基于生长指数（）推断，MWH的合成反应为扩散控制过程（3≤≤4），CH的合成反应为界面控制过程（2≤≤3）。分别测量了样品BH1TH和BH0TH的电流密度约为0.073和0.022 mA/m，表明前驱体与注入的微波之间的相互作用产生了带电自由基。通过X射线光电子能谱和傅里叶变换红外光谱确定这些自由基为OH基团。
