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Title: Intrinsic magnetic properties in Intrinsic magnetic properties of R(Fe1

Authors:
;
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1321968
Report Number(s):
IS-J 9040
Journal ID: ISSN 2469-9950; PRBMDO
DOE Contract Number:
AC02-07CH11358
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 94; Journal Issue: 2
Country of Publication:
United States
Language:
English

Citation Formats

Ke, Liqin, and Johnson, Duane D. Intrinsic magnetic properties in Intrinsic magnetic properties of R(Fe1. United States: N. p., 2016. Web. doi:10.1103/PhysRevB.94.024423.
Ke, Liqin, & Johnson, Duane D. Intrinsic magnetic properties in Intrinsic magnetic properties of R(Fe1. United States. doi:10.1103/PhysRevB.94.024423.
Ke, Liqin, and Johnson, Duane D. 2016. "Intrinsic magnetic properties in Intrinsic magnetic properties of R(Fe1". United States. doi:10.1103/PhysRevB.94.024423.
@article{osti_1321968,
title = {Intrinsic magnetic properties in Intrinsic magnetic properties of R(Fe1},
author = {Ke, Liqin and Johnson, Duane D.},
abstractNote = {},
doi = {10.1103/PhysRevB.94.024423},
journal = {Physical Review B},
number = 2,
volume = 94,
place = {United States},
year = 2016,
month = 7
}
  • A transfer function is presented for calculating magnetic field and flux density inside a test material as a result of surface measurement. By considering flux leakage, we introduce a parameter [eta], called the leakage coefficient, which can be experimentally determined. It is introduced into the equations to make the transfer function more practical. The distribution of field inside a test material is then discussed in accordance with a surface magnetic charge model.
  • Surface inspection of magnetic properties with a sensor is a useful and practical technique because it gives a rapid and noninvasive measurement and requires minimum material preparation. However, this technique is handicapped by the practical problems of calculating inherent magnetic properties of the material from such a measurement. A transfer function based on the first approximation was developed previously and it worked well when the dimension of the sample was comparable with the inspection head. However, the nonuniform distribution of the magnetic field is an inherent problem and gets more serious when the vertical and lateral dimensions of the testmore » material become comparable with the pole length of inspection head. Therefore, it invalidates the application of first approximation. A more general and practical transfer function is derived in this paper, including the geometry effects of inspection head and test material. This transfer function is based on the surface magnetic charge model and fits well in the situation when the test material has a large dimension. Test results on specimens by direct measurement and measurement from surface inspection will be presented.« less
  • The magnetic behavior of some R{sub 2}Fe{sub 17} single crystals have been analyzed quantitatively in a wide temperature range, using a two-sublattice approximation for the magnetic structure and taking into account isotropic exchange and single-ion crystal-field interactions. The 3d sublattice behavior has been described phenomenologically, from the study of the experimental magnetization results in a Y{sub 2}Fe{sub 17} single crystal. The parameters A{sub 2}{sup 0}, A{sub 4}{sup 0}, A{sub 6}{sup 0}, A{sub 6}{sup 6}, describing the crystal-field interaction in the different R{sub 2}Fe{sub 17} compounds (R=Er, Dy, Ho) have been determined. The calculated magnetic behavior shows good agreement with experimentalmore » magnetization results in the temperature range 4.2 to 300 K, demonstrating the reliability of the determined parameters. {copyright} {ital 1997} {ital The American Physical Society}« less
  • The use of synchrotron-based spectroscopy has revolutionized the way we look at matter. X-ray absorption spectroscopy (XAS) using linear and circular polarized light offers a powerful toolbox of element-specific structural, electronic, and magnetic probes that is especially well suited for complex materials containing several elements. We use the specific example of Zn1-xCoxO (Co:ZnO) to demonstrate the usefulness of combining these XAS techniques to unravel its intrinsic properties. We are able to demonstrate, that as long as phase separation or excessive defect formation is absent Co:ZnO is paramagnetic and we can establish independent quality indicators based on XAS. Samples which showmore » long-range magnetic order fail to meet the quality indicators and complementary experimental techniques such as x-ray diffraction and transmission electron microscopy indeed prove phase separation. By deconvoluting the XAS spectra, the characteristic spectral features of the phase separated materials are derived.« less
  • The use of synchrotron-based spectroscopy has revolutionized the way we look at matter. X-ray absorption spectroscopy (XAS) using linear and circular polarized light offers a powerful toolbox of element-specific structural, electronic and magnetic probes that is especially well suited for complex materials containing several elements. We use the specific example of Zn{sub 1-x}Co{sub x}O (Co:ZnO) to demonstrate the usefulness of combining these XAS techniques to unravel its intrinsic properties. We demonstrate that as long as phase separation or excessive defect formation is absent, Co:ZnO is paramagnetic. We can establish quantitative thresholds based on four reliable quality indicators using XAS; samplesmore » that show ferromagnet-like behaviour fail to meet these quality indicators, and complementary experimental techniques indeed prove phase separation. Careful analysis of XAS spectra is shown to provide quantitative information on the presence and type of dilute secondary phases in a highly sensitive, non-destructive manner.« less