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Title: Magnetostrictive materials and method for improving AC characteristics in same

Abstract

The present invention provides Terfenol-D alloys ("doped" Terfenol) having optimized performances under the condition of time-dependent magnetic fields. In one embodiment, performance is optimized by lowering the conductivity of Terfenol, thereby improving the frequency response. This can be achieved through addition of Group III or IV elements, such as Si and Al. Addition of these types of elements provides scattering sites for conduction electrons, thereby increasing resistivity by 125% which leads to an average increase in penetration depth of 80% at 1 kHz and an increase in energy conversion efficiency of 55%. The permeability of doped Terfenol remains constant over a wider frequency range as compared with undoped Terfenol. These results demonstrate that adding impurities, such as Si and Al, are effective in improving the ac characteristics of Terfenol. A magnetoelastic Gruneisen parameter, .gamma..sub.me, has also been derived from the thermodynamic equations of state, and provides another means by which to characterize the coupling efficiency in magnetostrictive materials on a more fundamental basis.

Inventors:
 [1];  [2]
  1. (Chicago, IL)
  2. (Ames, IA)
Issue Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA; Iowa State University, Ames, IA (US)
OSTI Identifier:
873927
Patent Number(s):
6273965
Application Number:
08/953,192
Assignee:
Iowa State University Research Foundation, Inc. (Ames, IA) AMES
DOE Contract Number:  
W-7405-ENG-82
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
magnetostrictive; materials; method; improving; characteristics; provides; terfenol-d; alloys; doped; terfenol; optimized; performances; condition; time-dependent; magnetic; fields; embodiment; performance; lowering; conductivity; frequency; response; achieved; addition; iii; elements; types; scattering; sites; conduction; electrons; increasing; resistivity; 125; leads; average; increase; penetration; depth; 80; khz; energy; conversion; efficiency; 55; permeability; remains; constant; wider; range; compared; undoped; results; demonstrate; adding; impurities; effective; magnetoelastic; gruneisen; parameter; gamma; derived; thermodynamic; equations; means; characterize; coupling; fundamental; basis; conversion efficiency; magnetic field; magnetic fields; energy conversion; frequency range; remains constant; penetration depth; coupling efficiency; magnetostrictive materials; magnetostrictive material; frequency response; conduction electrons; adding impurities; /148/420/

Citation Formats

Pulvirenti, Patricia P., and Jiles, David C. Magnetostrictive materials and method for improving AC characteristics in same. United States: N. p., 2001. Web.
Pulvirenti, Patricia P., & Jiles, David C. Magnetostrictive materials and method for improving AC characteristics in same. United States.
Pulvirenti, Patricia P., and Jiles, David C. Tue . "Magnetostrictive materials and method for improving AC characteristics in same". United States. https://www.osti.gov/servlets/purl/873927.
@article{osti_873927,
title = {Magnetostrictive materials and method for improving AC characteristics in same},
author = {Pulvirenti, Patricia P. and Jiles, David C.},
abstractNote = {The present invention provides Terfenol-D alloys ("doped" Terfenol) having optimized performances under the condition of time-dependent magnetic fields. In one embodiment, performance is optimized by lowering the conductivity of Terfenol, thereby improving the frequency response. This can be achieved through addition of Group III or IV elements, such as Si and Al. Addition of these types of elements provides scattering sites for conduction electrons, thereby increasing resistivity by 125% which leads to an average increase in penetration depth of 80% at 1 kHz and an increase in energy conversion efficiency of 55%. The permeability of doped Terfenol remains constant over a wider frequency range as compared with undoped Terfenol. These results demonstrate that adding impurities, such as Si and Al, are effective in improving the ac characteristics of Terfenol. A magnetoelastic Gruneisen parameter, .gamma..sub.me, has also been derived from the thermodynamic equations of state, and provides another means by which to characterize the coupling efficiency in magnetostrictive materials on a more fundamental basis.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2001},
month = {8}
}

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