Summary The optical changes in BaTiO3 are described, and it is shown that they can be completely explained if the crystal symmetry changes from tetragonal to orthorhombic at -5°C, and then to rhombohedral at -90°C. These changes have been confirmed by X-ray investigations, and it is concluded that the three transition…

Solid-state spectroscopy and crystallographyX-ray Diffraction in CrystallographyFerroelectric and Piezoelectric Materials

XCVI. Theory of barium titanate

A. F. Devonshire1949-10-01OpenAlex

Summary The theory of the dielectric and crystallographic properties of barium titanate is considered. By expanding the free energy as a function of polarization and strain and making reasonable assumptions about the coefficients, it is found possible to account for the various crystal transitions. Calculations are ma…

Thermal and Kinetic AnalysisFerroelectric and Piezoelectric MaterialsMicrowave Dielectric Ceramics Synthesis

Spontaneous emulsification of pure xylene in an aqueous solution through mere adsorption of a detergent in the interface

A. Kaminski、James W. McBain1949-09-07Proceedings of the Royal Society of London A Mathematical and Physical Sciences

Abstract Spontaneous emulsification of a pure liquid can occur. This is demonstrated when liquid hydrocarbons are quietly placed upon the surface of the solution of a suitable detergent. Here special attention has been given to xylene placed upon moderately dilute solutions of dodecylamine hydrochloride. In many cases…

Fluid Dynamics and MixingInnovative Microfluidic and Catalytic Techniques InnovationPickering emulsions and particle stabilization

Chemorheology of Polysulfide Rubbers

Marcos Mochulsky、A. V. Tobolsky1949-09-01Rubber Chemistry and Technology

Abstract Experimental results indicate that the socalled “cold flow” of polysulfide rubbers is almost certainly chemical rather than physical in nature. The term chemorheology has been adopted to describe this chemical type of plasticity. The experimental method employed in this investigation was the measurement of re…

Polymer crystallization and propertiesRheology and Fluid Dynamics StudiesPolymer Nanocomposites and Properties