Comparative study on phase development of lead titanate powders

Abstract Ž . Ultrafine lead titanate PbTiO powders in tetragonal form have been successfully prepared via two processing routes, 3 Ž . Ž . namely, conventional coprecipitation CPC and microemulsion-refined coprecipitation MCP . The formation process of lead titanate from the resulting precursors was monitored using techniques such as thermal analyses, FTIR spectroscopy, Raman scattering spectroscopy and X-ray diffraction for the phase identification. It was found that the microemulsion-refined processing route led to a lower formation temperature for lead titanate than that observed in the conventional coprecipitation route, and there is no detectable pyrochlore phase during the formation of PbTiO in the former case. The 3 two PbTiO powders have also been comparatively studied in particle morphology and specific surface areas. It indicates 3 that the microemulsion-refined coprecipitation is the technique that results in the formation of the finer powder of lead titanate than the conventional coprecipitation does in the present work.

Asymmetric spin-wave dispersion due to Dzyaloshinskii-Moriya interaction in an ultrathin Pt/CoFeB film

Employing Brillouin spectroscopy, strong interfacial Dzyaloshinskii-Moriya interactions have been observed in an ultrathin Pt/CoFeB film. Our micromagnetic simulations show that spin-wave nonreciprocity due to asymmetric surface pinning is insignificant for the 0.8nmthick CoFeB film studied. The observed high asymmetry of the monotonic spin wave dispersion relation is thus ascribed to strong Dzyaloshinskii-Moriya interactions present at the Pt/CoFeB interface. Our findings should further enhance the significance of CoFeB as an important material for magnonic, spintronic and skyrmionic applications.Comment: 12 pages, 4 figure

Direct observation of the Dzyaloshinskii-Moriya interaction in a Pt/Co/Ni film

The interfacial Dzyaloshinskii-Moriya interaction (DMI) in an in-plane anisotropic Pt(4nm)/Co(1.6nm)/Ni(1.6nm) film has been directly observed by Brillouin spectroscopy. It is manifested in the asymmetry of the measured magnon dispersion relation, from which the DMI constant has been evaluated. Linewidth measurements reveal that the lifetime of the magnons is asymmetric with respect to their counter-propagating directions. The lifetime asymmetry is dependent on the magnon frequency, being more pronounced the higher the frequency. Analytical calculations of the magnon dispersion relation and linewidth agree well with experiments.Comment: 15 pages, 4 figure

Method for producing sintered electroceramic materials from hydroxide and oxalate precursors

US6592805Granted Paten

Enhancement of spin-wave nonreciprocity in magnonic crystals via synthetic antiferromagnetic coupling

10.1038/srep10153Scientific Reports