Showing papers by "Mitsubishi Electric published in 1969"

Optical Spectra of Tm 3+ Ions in ZnSe:Tm, Li and ZnSe:Tm, Cu Crystals

Abstract: The absorption and luminescence spectra were observed below 77°K by using a high resolution spectrograph. The crystal field spectra show that the structures of some Tm 3+ centers are common to both of ZnSe:Tm, Cu and ZnSe:Tm, Li crystals. One of the common centers has a cubic symmetry and the crystal field parameters A 4 0 =15.1 cm -1 and A 6 0 =-2.5 cm -1 . The Tm 3+ ion in this center shows strong emission. Discussions on the model of this center and on the excitation mechanism are given.

Electron Microscopic Observation of Oxide Crystals Grown on Thin Film of α-Brass at Elevated Temperature

Abstract: Electrolytically-thinned α-brass foils containing dislocations, stacking faults and grain boundaries are heated at the temperatures between 200°C and 600°C in the air pressures between 1×10-4 Torr and 760 Torr in order to investigate the relation between the crystal imperfections and the oxide crystals formed on the surface. It is observed in the electron microscopic images that the particles of ZnO, Cu2O and CuO are formed on the surface of the specimen corresponding to heating conditions without any special relation to the imperfections in α-brass. It is also observed that hexagonal or irregular shaped thin regions are formed in the specimen by the evaporation of α-brass in the air pressures below 4 Torr at above 400°C. When the specimens of a few microns in thickness are heated, the needle-shaped zinc oxide crystals grow on the surface of α-brass with the axis of [100]. Sometimes drop-like particles are formed on the walls and at the tips of the needles. The evaporation mechanism of α-brass during oxidation and the role of drops to the crystal growth of needles are discussed.

CW Gunn Diodes in Composite Structure

Abstract: It is a way of obtaining a higher output power to operate microwave generators in parallel combinations. It was already reported that several watts of output were obtained with impatt diodes in parallel and series combinations. While, such the attempt at Gunn diodes in CW operation is not seen yet, except for a case of 300 mW output in X-band with a cascaded Gunn oscillator. The present report is related to experimental results of Gunn diodes in composite structure.