Dynamics of birefringence properties in 17/30/70 PLZT ceramics

Birefringent properties of PLZT ceramics (Pb₈₃La₁₇)(Zr₃₀Ti₇₀)O₃ were investigated by measuring the transverse electrooptic effect in a 0.2 mm-thick wafer at various speeds of external voltage changes. At least two types of internal polarized microregions of different physical nature in charge of the electrooptical properties are observed.     

Calculation of orbital magnetic moments of π-electron terms of cyclic molecules in a collective-motion model

The magnetic moments of levels of ring -electron chains along a cyclic core of a molecule are calculated for various values of the form factor of the periodic potential of the -core field. The cases of short-range (flexible chain) and long-range (rigid chain) strong interelectron repulsion are considered. The magnetic moments of the flexible-chain levels are practically independent of the form factor. The magnetic moments of the rigid-chain levels are less than the corresponding moments of the flexible chain, but at certain values of the form factor resonance occurs and the rigid-chain moments approach those of the flexible chain. An anomalously large Zeeman splitting of the upper electron levels of large aromatic molecules is predicted.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 37–42, October, 1976.