Gancheva Maria, Iordanova Reni, Koseva Iovka, Avdeev Georgi, Burdina Gergana, Ivanov Petar
Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, "Acad. G. Bonchev" Str., bl. 11, 1113 Sofia, Bulgaria.
Institute of Physical Chemistry "Acad. Rostislaw Kaischew", Bulgarian Academy of Sciences, "Acad. G. Bonchev" Str., bl. 11, 1113 Sofia, Bulgaria.
Materials (Basel). 2023 Nov 3;16(21):7025. doi: 10.3390/ma16217025.
BaMoO was obtained via facile mechanochemical synthesis at room temperature and a solid-state reaction. An evaluation of the phase composition and structural and optical properties of BaMoO was conducted. The influence of different milling speeds on the preparation of BaMoO was explored. A shorter reaction time for the phase formation of BaMoO was achieved using a milling speed of 850 rpm. A milling speed of 500 rpm led to partial amorphization of the initial reagents and to prolongation of the synthesis time of up to 3 h of milling time. Solid-state synthesis was performed via heat treatment at 900 °C for 15 h. X-ray diffraction analysis (XRD), infrared (IR) and UV diffuse reflectance (UV-Vis) and photoluminescence (PL) spectroscopy were carried out to characterize the samples. Independently of the method of preparation, the obtained samples had tetragonal symmetry. The average crystallite sizes of all samples, calculated using Scherrer's formula, were in the range of 240 to 1540 Å. IR spectroscopy showed that more distorted structural MoO units were formed when the compound was synthesized via a solid-state reaction. The optical band gap energy of the obtained materials was found to decrease from 4.50 to 4.30 eV with increasing crystallite sizes. Green- and blue-light emissions were observed for BaMoO phases under excitation wavelengths of 330 and 488 nm. It was established that the intensity of the PL peaks depends on two factors: the symmetry of MoO units and the crystallite sizes.
通过室温下简便的机械化学合成法和固态反应制得了钼酸钡（BaMoO）。对钼酸钡的相组成、结构和光学性质进行了评估。探究了不同研磨速度对钼酸钡制备的影响。使用850转/分钟的研磨速度实现了钼酸钡相形成的较短反应时间。500转/分钟的研磨速度导致初始试剂部分非晶化，并使合成时间延长至长达3小时的研磨时间。固态合成是通过在900℃下热处理15小时进行的。进行了X射线衍射分析（XRD）、红外（IR）、紫外漫反射（UV-Vis）和光致发光（PL）光谱分析以表征样品。无论制备方法如何，所获得的样品都具有四方对称性。使用谢乐公式计算的所有样品的平均微晶尺寸在240至1540埃的范围内。红外光谱表明，当通过固态反应合成该化合物时，会形成更多扭曲的结构MoO单元。发现所获得材料的光学带隙能量随着微晶尺寸的增加从4.50电子伏特降至4.30电子伏特。在330和488纳米的激发波长下，观察到钼酸钡相发出绿色和蓝色光。已确定PL峰的强度取决于两个因素：MoO单元的对称性和微晶尺寸。
