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Browse Prior Art Database

High Contrast Nonvolatile Reversible Medium for Low Energy Laser Writing

IP.com Disclosure Number: IPCOM000080878D
Original Publication Date: 1974-Feb-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Holtzberg, F: AUTHOR [+2]

Abstract

A technique is described for reducing the pressure required for semiconductor to metal transition in SmS.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

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High Contrast Nonvolatile Reversible Medium for Low Energy Laser Writing

A technique is described for reducing the pressure required for semiconductor to metal transition in SmS.

Heretofore, the dark blue-black semiconducting phase of SmS has been transformed to a gold metallic phase, either by a semiconductor metal transition at 6.5 K bar and room temperature (reversible) or by polishing the surface of a crystal of the semiconductor (nonreversible). It has also been shown that laser pulses of the order of nanojoules can convert the polished gold surface to the semiconducting blue-black color. However, another technique has not been developed for conversion of the blue-black phase to gold phase, other than the methods described above.

It has been determined that chemical doping of SmS with a smaller trivalent ion has an effect similar to pressure in converting the blue-black phase to gold phase.

Solid solution systems such as Sm(1-x) RE(x)S (RE = La, Y, Gd) and SmS(1- x)As(x) have been demonstrated to lower the transition pressure to atmospheric pressure for specific compositions. Such systems provide a means of optimizing these materials for reversible laser beam writing in memory applications using, for example, a strain mechanism.

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