Quiñones-Gurrola José Remigio, Rendón-Angeles Juan Carlos, Matamoros-Veloza Zully, López-Cuevas Jorge, Pérez-Garibay Roberto, Yanagisawa Kazumichi
Centre for Research and Advanced Studies of the National Polytechnic Institute, Saltillo Campus, Ramos Arizpe 25900, Mexico.
Tecnológico Nacional de México/(I.T. Saltillo), Technological Institute of Saltillo, Graduate Division, Saltillo 25280, Mexico.
Nanomaterials (Basel). 2023 Jul 28;13(15):2195. doi: 10.3390/nano13152195.
In recent decades, perovskite-type compounds (ABB'O) have been exhaustively studied due to their unique ferroelectric properties. In this work, a systematic study aiming to prepare fine particles in the binary system SrZrO-SrTiO was conducted under hydrothermal conditions in a KOH (5 M) solution at 200 °C for 4 h under a constant stirring speed of 130 rpm. The precursors employed were SrSO powder (<38 μm size) and coprecipitated hydrous gels of Zr(OH)•9.64 HO (Zr-gel) and Ti(OH)•4.5HO (Ti-gel), which were mixed according to the stoichiometry of the SrZrTiO in the compositional range of 0.0 > x > 100.0 mol% Ti. The XRD results revealed the formation of two crystalline phases rich in Zr, an orthorhombic structured SrZrTiO and a cubic structured SrZrTiO within the compositional range of 0.1-0.5 mol of Ti. A cubic perovskite structured solid solution, SrTiZrO, was preferentially formed within the compositional range of 0.5 > x > 0.1 mol% Ti. The SrZrO and SrZrTiO-rich phases had particle sizes averaging 3 μm with a cubic morphology. However, a remarkable reduction in the particle size occurred on solid solutions prepared with hydrous Ti-gel over contents of 15 mol% Ti in the reaction media, resulting in the formation of nanosized particle agglomerates with a cuboidal shape self-assembled via a 3D hierarchical architecture, and the sizes of these particles varied in the range between 141.0 and 175.5 nm. The limited coarsening of the particles is discussed based on the Zr-gel and Ti-gel dehydration capability differences that occurred under hydrothermal processing.
近几十年来，钙钛矿型化合物（ABB'O）因其独特的铁电性能而受到广泛研究。在本工作中，在水热条件下，于200℃的5M KOH溶液中，以130rpm的恒定搅拌速度进行了4小时的系统研究，旨在制备二元体系SrZrO - SrTiO中的细颗粒。所用前驱体为SrSO粉末（尺寸<38μm）以及Zr(OH)•9.64HO（Zr - 凝胶）和Ti(OH)•4.5HO（Ti - 凝胶）的共沉淀水合凝胶，它们按照SrZrTiO在0.0 > x > 100.0 mol% Ti组成范围内的化学计量比混合。XRD结果表明，在0.1 - 0.5 mol Ti的组成范围内形成了两种富含Zr的晶相，一种是正交结构的SrZrTiO，另一种是立方结构的SrZrTiO。在0.5 > x > 0.1 mol% Ti的组成范围内优先形成了立方钙钛矿结构的固溶体SrTiZrO。富含SrZrO和SrZrTiO的相平均粒径为3μm，呈立方形态。然而，当反应介质中Ti的含量超过15 mol%时，用含水Ti - 凝胶制备的固溶体颗粒尺寸显著减小，形成了通过三维分级结构自组装的立方体形纳米级颗粒团聚体，这些颗粒的尺寸在141.0至175.5nm之间变化。基于水热过程中Zr - 凝胶和Ti - 凝胶脱水能力的差异，讨论了颗粒有限的粗化现象。
