Tihtih Mohammed, Ibrahim Jamal Eldin F M, Basyooni Mohamed A, En-Nadir Redouane, Hussainova Irina, Kocserha István
Institute of Ceramics and Polymer Engineering, University of Miskolc, Egyetemvaros, MiskolcH-3515, Hungary.
Department of Materials Technology, University of Bahri, Khartoum12217, Sudan.
ACS Omega. 2023 Jan 25;8(5):5003-5016. doi: 10.1021/acsomega.2c07660. eCollection 2023 Feb 7.
The BTO, BFTC, and BCTF compounds were synthesized by the sol-gel method. The XRD study revealed the formation of single-phase tetragonal perovskite structures with the space group (P4mm). The crystalline parameters were studied as a function of Fe and Co contents and occupation of Ba and/or Ti sites by Fe and Co in the BTO lattice. It was found that the obtained strain increases when Ba is substituted by Co and Ti by Fe. The Raman investigation confirmed the existence of three active modes (B1/E (TO1LO), (E (TO)/A1(TO3), and (A 1(LO)/E (TO), all of which are related to the existence of the tetragonal phase and strongly support the XRD results. The microstructural study showed a clear correlation between the presence of Fe and Co and the grain size distribution. Optical studies revealed the improvement in band gap energy with transition-metal (Fe and Co) co-doped BTO ceramics. The decrease in the band gap is explained by the competing effects of Columbian interactions, microdeformation, and oxygen defects. The results indicate that the presence of Fe and Co dopants enhances the absorption in the BTO ceramic. The dopants demonstrated an effect on thermal conductivity: they decreased the thermal conductivity of BTO, which is in the range of 0.76-2.23 W m K at room temperature and 2.02-0.27 W m K at elevated temperatures. The microstructure of the manufactured materials and the grain size distribution affect the compressive strength.
BTO、BFTC和BCTF化合物通过溶胶-凝胶法合成。XRD研究表明形成了具有空间群（P4mm）的单相四方钙钛矿结构。研究了晶体参数与铁和钴含量以及BTO晶格中铁和钴对钡和/或钛位点的占据情况之间的函数关系。发现当钴取代钡且铁取代钛时，所获得的应变增加。拉曼研究证实存在三种活性模式（B1/E（TO1LO）、（E（TO）/A1（TO3）和（A1（LO）/E（TO）），所有这些都与四方相的存在有关，并有力地支持了XRD结果。微观结构研究表明铁和钴的存在与晶粒尺寸分布之间存在明显的相关性。光学研究表明，过渡金属（铁和钴）共掺杂的BTO陶瓷的带隙能量有所改善。带隙的减小是由库仑相互作用、微变形和氧缺陷的竞争效应来解释的。结果表明，铁和钴掺杂剂的存在增强了BTO陶瓷的吸收。掺杂剂对热导率有影响：它们降低了BTO的热导率，室温下热导率在0.76 - 2.23 W m K范围内，高温下在2.02 - 0.27 W m K范围内。所制造材料的微观结构和晶粒尺寸分布会影响抗压强度。
