Advanced Nano-Finishing Process of SrTiO₃ Substrate by Cluster MR-Effect Plate

Abstract

As a new multifunctional material, strontium titanate (SrTiO3) ceramic has a wide application in grain boundary layer capacitor (GBLC) with the microstructure characteristics of semi-conductive crystalline grain and insulated boundary. An ultra-precision nanofishing technique is developed to lap and polish the brittle and thin SrTiO3 substrate with the cluster MR-effect plate where the abrasives are constrained by the cluster MR-effect chains, under the influence of a magnetic field, the carbonyl iron particles (CIPs) and non-magnetic abrasive particles remove material from the surface of workpiece being machined in this paper. Mahr XT20 roughmeter, Keyence VHX-600 and Olympus S4000 microscopes are used to investigate the characteristic of machined surface and the mechanism of material removal. An ultra-smooth planarization surface of SrTiO3 substrate with surface roughness Ra 3.8 nm (Mahr), RMS 0.973 nm (Veeco interferometer) is obtained under a high efficiency. It is found that the pore structures of the sintered substrate would weak the machinability of SrTiO3 and influence the further improvement of surface quality.

An experimental analysis of strontium titanate ceramic substrates polished by magnetorheological finishing with dynamic magnetic fields formed by rotating magnetic poles

“…They also obtained STO substrates with a surface roughness, removal rate, and thickness of Ra 0.268 μm, 4.6 μm min −1 , and 0.19 mm, respectively. Bai et al [21] polished brittle and thin STO substrate with an ultraprecise nano-finishing technique with a cluster magnetorheological (MR)-effect plate where the abrasives are constrained by the cluster MR-effect chains, under the influence of a magnetic field. A regional ultra-smooth planarization surface of STO substrate where a surface roughness of Ra being 3.8 nm (Mahr), rms 0.973 nm (Veeco interferometer) was obtained.…”