A method of determining the stress-strain relation of materials when stresses are applied for times of the order of 20 microseconds is described. The apparatus employed was a modification of the Hopkinson pressure bar, and detonators were used to produce large transient stresses. Thin specimens of rubbers, plastics an…

Laser-Plasma Interactions and DiagnosticsNuclear Physics and ApplicationsHigh-Velocity Impact and Material Behavior

The Dielectric Properties of Barium Titanate at Low Temperatures

R. F. Blunt、W. F. Love1949-10-15Physical Review

The complex dielectric constatn of ceramic barium titanate has been measured as a function of temperature from 300\ifmmode^\circ\else\textdegree\fi{}K down to 2.8\ifmmode^\circ\else\textdegree\fi{}K. The large value of the slope of the real part of the dielectric constant, ${K}^{\ensuremath{'}}$, versus temperature cu…

Ferroelectric and Piezoelectric MaterialsMicrowave Dielectric Ceramics SynthesisDielectric properties of ceramics

Domain Structures and Phase Transitions in Barium Titanate

P. W. Forsbergh1949-10-15Physical Review

The arrangements of domains that arise in single crystals of barium titanate in the ferroelectric tetragonal phase have been studied in detail. The domains are the results of tetragonal (101) twinning, and appear by the formation of wedge-shaped laminar domains between two converging (101) twin planes. The distance of…

Solid-state spectroscopy and crystallographyMaterial Science and ThermodynamicsOptical and Acousto-Optic Technologies

Detection of Antiferromagnetism by Neutron Diffraction

C. G. Shull、J. S. Smart1949-10-15OpenAlex

T necessary conditions for the existence of ferromagnetism are: (1) the atoms must have a net magnetic moment due to an unfilled electron shell, and (2) the exchange integral / relating to the exchange of electrons between neighboring atoms must be positive. This last condition is required in order that spin states of…

X-ray Diffraction in CrystallographyNuclear Physics and Applications