Study of Se–Te–Sb System for Application to Reversible Optical Data Storage

Abstract

In the present work variation of the two main parameters–viscosity and critical cooling rate, required for the recent upcoming optical data storage devices, have been analysed for different compositions of Se80-x Sb x Te20 (0≤x≤9) system. Temperature dependence of viscosity has been determined using the activation energy for glass transition and for crystallization obtained from heating rate dependence of glass transition temperature and peak crystallization temperature from DSC measurements. Vicsocity has been estimated with the help of Vogel-Tamman-Fulcher equation. It has been found that for samples containing Sb≤4 at.%, the viscosity increases with the increase in Sb content. Further increase in Sb concentration causes a decrease in the viscosity. These results are consistent with the structural changes taking place in the Se–Te system with increase in Sb content. Using these values of viscosity and kinetics of crystal nucleation and growth process, the time-temperature-transformation curves were obtained. The critical cooling rate R c is found to increase for Sb>4 at.%. For good reversible phase change optical recording, the critical cooling rate of the material should be high enough so as to get an erasure time of less than 1 µs. From the analysis of the data the suitability of the SeTeSb system for optical recording has been discussed.

Optical and electrical properties of as-prepared and annealed (Se80Te20)100−xAgx (0≤x≤4) ultra-thin films

“…To improve its properties, certain additives are used. Glassy alloys of the Se-Te system have become materials of considerable commercial importance and are widely used for optical recording media because of their excellent laser writing sensitivity in xerography, and electrographic applications such as photoreceptors in photocopying and laser printing [5] but these advantages depend on material stability [6]. Experimental results reported by various workers have shown that the addition of impurity atoms in binary Se-Te systems changes the optical properties of chalcogenide glassy semiconductors.…”

Crystallization Mechanisms of some Se100–xTex Glassy Alloys

“…2,3 There are promising applications in the field of laser surgery and radiometric low-temperature measurement. 5 Glassy alloys of the Se -Te system based on selenium have become materials of considerable commercial importance and are widely used for optical recording media because of their excellent laser writer sensitivity, 6 but these advantages depend on material stability. 4 Sulfide glasses exhibit an excellent 3-5 mm spectral band due to overtone absorptions of the fundamental cation-sulfur bonds such as Ge-S (As-S) which cut off the transmission between 10 and 11 mm in the 1 mm thick glass sample.…”

Optical properties of Se–Te–Sb thin films

“…Chalcogenide glassy alloys based on amorphous Se have found various applications in different fields, such as: optical recording media because of their excellent laser writer sensitivity [12,13], infrared spectroscopy [14], transistors, detectors [15,16], rectifiers, photocells, switching, memories [17], xerography, and electrographic applications such as photoreceptors in photocopying, laser printing [18], and laser fiber techniques [19][20][21][22]. In the pure state Se has disadvantages because of its short lifetime and low sensitivity [23].…”