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Title: Emerging Magnetism Arising from Self-Damage in (alpha) and (delta)-Pu

Abstract

As a consequence of the unusual nature of plutonium's electronic structure, point- and extended-defects are expected to, and do exhibit extraordinary properties[1]. Low temperature magnetic susceptibility measurements on Pu and fcc-Pu(Ga) show that the magnetic susceptibility increases as a function of time, yet upon annealing the specimen returns to its initial magnetic susceptibility. This excess magnetic susceptibility (EMS) arises from the {alpha}-decay and U recoil damage cascades which produce vacancy and interstitials as point and extended defects. The temperature of the first annealing stage defines a temperature (<35K) below which we are able to characterize the time and temperature evolution of the accumulating damage cascades as being a saturation function. The temperature dependence of the EMS is well described by a time independent, Curie-Weiss curve arising from a volumetric region surrounding each U damage cascade. This saturation picture also leads directly to a determination of the microscopic volume of the specimen that is affected by the frozen-in damage cascade. For our measurements in d-Pu we calculate a diameter of the magnetically affected volume of {approx} 250 {angstrom} per damage cascade. This should be compared with an estimated volume that encloses the damage cascade itself (determined from molecular dynamics) of {approx}100more » {angstrom}. Hence, the ratio of these volumes is {approx}8. The observed anomalous magnetic behavior is likely a consequence of the highly correlated nature of the electrons. Similarities with defects in hole-doped superconductors suggest a general phenomenon in strongly correlated electron systems, of which Pu may be a particularly unusual or special example.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
894789
Report Number(s):
UCRL-JRNL-217247
TRN: US0700316
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Society Symposium Proceedings, vol. 893, N/A, March 1, 2006, pp. 0893-JJ04-03.1-11
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; DEFECTS; ELECTRONIC STRUCTURE; ELECTRONS; INTERSTITIALS; MAGNETIC SUSCEPTIBILITY; MAGNETISM; SATURATION; SUPERCONDUCTORS; TEMPERATURE DEPENDENCE

Citation Formats

McCall, S K, Fluss, M J, Chung, B W, Chapline, G F, Jackson, D D, and McElfresh, M W. Emerging Magnetism Arising from Self-Damage in (alpha) and (delta)-Pu. United States: N. p., 2005. Web.
McCall, S K, Fluss, M J, Chung, B W, Chapline, G F, Jackson, D D, & McElfresh, M W. Emerging Magnetism Arising from Self-Damage in (alpha) and (delta)-Pu. United States.
McCall, S K, Fluss, M J, Chung, B W, Chapline, G F, Jackson, D D, and McElfresh, M W. Wed . "Emerging Magnetism Arising from Self-Damage in (alpha) and (delta)-Pu". United States. doi:. https://www.osti.gov/servlets/purl/894789.
@article{osti_894789,
title = {Emerging Magnetism Arising from Self-Damage in (alpha) and (delta)-Pu},
author = {McCall, S K and Fluss, M J and Chung, B W and Chapline, G F and Jackson, D D and McElfresh, M W},
abstractNote = {As a consequence of the unusual nature of plutonium's electronic structure, point- and extended-defects are expected to, and do exhibit extraordinary properties[1]. Low temperature magnetic susceptibility measurements on Pu and fcc-Pu(Ga) show that the magnetic susceptibility increases as a function of time, yet upon annealing the specimen returns to its initial magnetic susceptibility. This excess magnetic susceptibility (EMS) arises from the {alpha}-decay and U recoil damage cascades which produce vacancy and interstitials as point and extended defects. The temperature of the first annealing stage defines a temperature (<35K) below which we are able to characterize the time and temperature evolution of the accumulating damage cascades as being a saturation function. The temperature dependence of the EMS is well described by a time independent, Curie-Weiss curve arising from a volumetric region surrounding each U damage cascade. This saturation picture also leads directly to a determination of the microscopic volume of the specimen that is affected by the frozen-in damage cascade. For our measurements in d-Pu we calculate a diameter of the magnetically affected volume of {approx} 250 {angstrom} per damage cascade. This should be compared with an estimated volume that encloses the damage cascade itself (determined from molecular dynamics) of {approx}100 {angstrom}. Hence, the ratio of these volumes is {approx}8. The observed anomalous magnetic behavior is likely a consequence of the highly correlated nature of the electrons. Similarities with defects in hole-doped superconductors suggest a general phenomenon in strongly correlated electron systems, of which Pu may be a particularly unusual or special example.},
doi = {},
journal = {Materials Research Society Symposium Proceedings, vol. 893, N/A, March 1, 2006, pp. 0893-JJ04-03.1-11},
number = ,
volume = ,
place = {United States},
year = {Wed Nov 16 00:00:00 EST 2005},
month = {Wed Nov 16 00:00:00 EST 2005}
}