Preparation of Barium Titanate and Strontium Titanate Nanocube Particles and their Accumulation Using Smart Glue

Abstract

Barium titanate (BaTiO3, BT) and strontium titanate (SrTiO3, ST) nanocube particles were successfully prepared by a solvothermal method. The prepared particles were collected by a centrifugal separator. The X-ray diffraction (XRD) measurement confirmed the formation of perovskite BT and ST nanoparticles with sizes of around 17 nm while a transmittance electron microscope (TEM) observation revealed formation of cubic-shaped nanoparticles with sharp edge and corner. These nanocube particles were monodistributed in hexane with tri-n-octylphosphine oxide (TOPO) as dispersant, separately, and then, the 2-dimentional checkerboard-structured accumulations composed of the BT and ST nanocubes were built up using DNA base pair such as adenine and thymine as smart glue. TEM observation confirmed that a part of accumulations had a checkerboard-structure.

Dispersion of barium titanate and strontium titanate nanocubes and their selective accumulations

“…10) A mixture of ethanol and 2-metoxy-ethanol was used as the solvent, while TiO 2 (Ishihara Sangyo Kaisha LTD., >99.9%, size: 7 nm), Ba(OH) 2 (Strem Chemicals, >99.9%), and Sr(OH) 2 (Ube Materials Industries Co., LTD., >99.9%) were used as raw materials. The obtained powders were collected by a centrifugal separator.…”

“…From TEM observation of each BT and ST nanocube particle, surface of nanocube was assigned to {100} planes. 10) Thus, these nanocube accumulations had interface boundary of {100}. In this study, our objective is a formation of BT/ST accumulations with hetrointerface.…”

“…Since these nanocubes were covered by organic molecules, chemical composition analysis was not applied. Thus, on the basis of different characteristic microstructure between BT (elastically strained structure) and ST (no strained structure) nanocubes, 10) each nanocube in Fig. 5 were assigned to BT and ST. From Fig.…”

“…10) However, this method exhibited two problems as follows, i.e., (1) difficulty of removal of TOPO by heat treatment owing to large molecular weight of 386.64 g/mol, and (2) high cost of DNA basic pair. Thus, in this study, the first objective is proposal of new dispersant with smaller molecular weight than TOPO, and the second objective is proposal of new smart glue with lower cost than DNA basic pair.…”

Microwave synthesis of KNbO₃ nanocubes

“…We have been studying the preparation of nanocubes with the perovskite structure, such as barium titanate (BaTiO 3 ), 1) strontium titanate (SrTiO 3 ), 2) barium zirconate (BaZrO 3 ), 3),4) strontium zirconate (SrZrO 3 ), 5) sodium niobate (NaNbO 3 ), and potassium niobate (KNbO 3 ). 6), 7) These nanocubes were synthesized by a wet chemical reaction.…”