Browse Prior Art Database

Niobium Bismuth Mestastable Alloys

IP.com Disclosure Number: IPCOM000075179D
Original Publication Date: 1971-Aug-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR [+3]

Abstract

Niobium-bismuth (Nb-Bi) alloy films have been prepared by radio-frequency sputtering from an unalloyed cathode target of the elements. The film compositions ranged from a few tenth's weight percent Bi to several weight percent, i.e., from below the detection limits of an electron microprobe which is approx. 0.15 wt. % to about 16 wt. % which is the maximum amount of Bi measured. It is to be noted that Nb and Bi are practically insoluble in each other. The Nb-Bi metastable alloy has been used as the base electrode of a bistable resistor which when fabricated has suitable properties.

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

Page 1 of 1

Niobium Bismuth Mestastable Alloys

Niobium-bismuth (Nb-Bi) alloy films have been prepared by radio-frequency sputtering from an unalloyed cathode target of the elements. The film compositions ranged from a few tenth's weight percent Bi to several weight percent, i.e., from below the detection limits of an electron microprobe which is approx. 0.15 wt. % to about 16 wt. % which is the maximum amount of Bi measured. It is to be noted that Nb and Bi are practically insoluble in each other. The Nb-Bi metastable alloy has been used as the base electrode of a bistable resistor which when fabricated has suitable properties.

The nature of the metastable Nb-Bi material is also shown by:

(a) The uniformity of the Nb-Bi ratio as the

samples are microprobed from point-to-point.

(b) Suppression of the superconducting transition

temperature (T(c)), e.g., with 1.2 wt. %, Nb-Bi

has a T of 7.1 degrees K, whereas pure Nb has a T(c)

of 9.2 degrees K.

The compositions hereof have been prepared by radio-frequency sputtering technique from a coelement target consisting of either an evaporated pattern of Bi dots on an Nb cathode, or melted Bi in a pattern of holes on a niobium cathode. The composition of the resulting film can be controlled by adjusting the relative amount of Bi on the cathode. Additional compositional control can be obtained by varying the sputtering parameters.

1