skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Intrinsic nanostructure in Zr2-xFe4Si16-y (x=0.81, y=6.06)

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1160058
Report Number(s):
BNL-106211-2014-JA
R&D Project: MA015; KC0201010
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: JOURNAL OF PHYSICS-CONDENSED MATTER; Journal Volume: 26; Journal Issue: 37
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Smith G. J., Wu L., Simonson, J. W., Orvis, T., Marques, C., Grose, J. E., Kistner-Morris, J. J., Cho, K., Kim, H., Tanatar, M. A., Garlea, V. O., Prozorov, R., Zhu, Y., and Aronson, M. C. Intrinsic nanostructure in Zr2-xFe4Si16-y (x=0.81, y=6.06). United States: N. p., 2014. Web. doi:10.1088/0953-8984/26/37/376002.
Smith G. J., Wu L., Simonson, J. W., Orvis, T., Marques, C., Grose, J. E., Kistner-Morris, J. J., Cho, K., Kim, H., Tanatar, M. A., Garlea, V. O., Prozorov, R., Zhu, Y., & Aronson, M. C. Intrinsic nanostructure in Zr2-xFe4Si16-y (x=0.81, y=6.06). United States. doi:10.1088/0953-8984/26/37/376002.
Smith G. J., Wu L., Simonson, J. W., Orvis, T., Marques, C., Grose, J. E., Kistner-Morris, J. J., Cho, K., Kim, H., Tanatar, M. A., Garlea, V. O., Prozorov, R., Zhu, Y., and Aronson, M. C. Thu . "Intrinsic nanostructure in Zr2-xFe4Si16-y (x=0.81, y=6.06)". United States. doi:10.1088/0953-8984/26/37/376002.
@article{osti_1160058,
title = {Intrinsic nanostructure in Zr2-xFe4Si16-y (x=0.81, y=6.06)},
author = {Smith G. J. and Wu L. and Simonson, J. W. and Orvis, T. and Marques, C. and Grose, J. E. and Kistner-Morris, J. J. and Cho, K. and Kim, H. and Tanatar, M. A. and Garlea, V. O. and Prozorov, R. and Zhu, Y. and Aronson, M. C.},
abstractNote = {},
doi = {10.1088/0953-8984/26/37/376002},
journal = {JOURNAL OF PHYSICS-CONDENSED MATTER},
number = 37,
volume = 26,
place = {United States},
year = {Thu Aug 28 00:00:00 EDT 2014},
month = {Thu Aug 28 00:00:00 EDT 2014}
}
  • We present a study of the crystal structure and physical properties of single crystals of a new Fe-based ternary compound, Zr2 xFe4Si16 y (x = 0.81, y = 6.06). Zr1.19Fe4Si9.94 is a layered compound, where stoichiometric -FeSi2-derived slabs are separated by Zr-Si planes with substantial numbers of vacancies. High resolution transmission electron microscopy (HRTEM) experiments show that these Zr-Si layers consist of 3.5 nm domains where the Zr and Si vacancies are ordered within a supercell sixteen times the volume of the stoichiometric cell. Within these domains, the occupancies of the Zr and Si sites obey symmetry rules that permitmore » only certain compositions, none of which by themselves reproduce the average composition found in x-ray diffraction experiments. Magnetic susceptibility and magnetization measurements reveal a small but appreciable number of magnetic moments that remain freely fluctuating to 1.8 K, while neutron diffraction confirms the absence of bulk magnetic order with a moment of 0.2 B or larger down to 1.5 K. Electrical resistivity measurements find that Zr1.19Fe4Si9.94 is metallic, and the modest value of the Sommerfeld coefficient of the specific heat = C/T suggests that quasi-particle masses are not particularly strongly enhanced. The onset of superconductivity at Tc 6 K results in a partial resistive transition and a small Meissner signal, although a bulk-like transition is found in the specific heat. Sharp peaks in the ac susceptibility signal the interplay of the normal skin depth and the London penetration depth, typical of a system in which nano-sized superconducting grains are separated by a non-superconducting host. Ultra low field differential magnetic susceptibility measurements reveal the presence of a surprisingly large number of trace magnetic and superconducting phases, suggesting that the Zr-Fe-Si ternary system could be a potentially rich source of new bulk superconductors.« less
  • We present a study of the crystal structure and physical properties of single crystals of a new Fe-based ternary compound, Zr 2-xFe 4Si 16-y(x=0.81,y=6.06). Zr 1.19Fe 4Si 9.94 is a layered compound, where stoichiometric β-FeSi 2-derived slabs are separated by Zr-Si planes with substantial numbers of vacancies. High resolution transmission electron microscopy (HRTEM) experiments show that these Zr-Si layers consist of 3.5nm domains where the Zrand Si vacancies are ordered within a supercell sixteen times the volume of the stoichiometric cell. Within these domains, the occupancies of the Zr and Si sites obey symmetry rules that permit only certain compositions,more » none of which by themselves reproduce the average composition found in x-ray diffraction experiments. Magnetic susceptibility and magnetization measurements reveal a small but appreciable number of magnetic moments that remain freely fluctuating to 1.8K, while neutron diffraction confirms the absence of bulk magnetic order with a moment of 0.2μB or larger down to 1.5K. Electrical resistivity measurements find that Zr 1.19Fe 4Si 9.94 is metallic, and the modest value of the Sommerfeld coefficient of the specific heat γ = C/T suggests that quasi-particle masses are not particularly strongly enhanced. The onset of superconductivity at T c ≃ 6K results in a partial resistive transition and a small Meissner signal, although a bulk-like transition is found in the specific heat. Sharp peaks in the ac susceptibility signal the interplay of the normal skin depth and the London penetration depth, typical of a system in which nano-sized superconducting grains are separated by a on-superconducting host. Ultra low field differential magnetic susceptibility measurements reveal the presence of a surprisingly large number of trace magnetic and superconducting phases, suggesting that the Zr-Fe-Si ternary system could be a potentially rich source of new bulk superconductor.« less
  • A set of Fe-based amorphous alloys, Fe{sub 93{minus}x{minus}y}Zr{sub 7}B{sub x}Cu{sub y}, with x=4, 6, 8, or 12, and y=0 or 2 has been systematically characterized in their ability to form nanocrystalline, magnetically soft material via annealing in the range of 430{endash}600{degree}C. Conventional M{umlt o}ssbauer spectroscopy is used to follow the degree of bcc-Fe formation as well as changes in the hyperfine field distribution of the amorphous phase as a function of anneal temperature. Copper plays a strong role in the bcc-Fe formation for x=12 but less of a role for x=8 and 6. Unconventional M{umlt o}ssbauer studies utilizing radio frequencymore » (rf) fields provide information on the soft magnetic nature of the alloys by observing the degree of rf-induced collapse of the hyperfine fields. The M{umlt o}ssbauer experiment in which the rf collapse and rf sideband effects are used allows the soft nanocrystalline bcc phase to be distinguished from magnetically harder microcrystalline {alpha}-Fe. The rf M{umlt o}ssbauer technique, being particularly sensitive to the magnetic anisotropy, provides information on the anisotropy fields and hence on the grain size distribution. X-ray diffraction (XRD) is used to estimate the bcc-Fe grain size based on the diffraction peak linewidths. Average grain sizes of 5{endash}14 nm are found for 500{endash}550{degree}C annealed specimens where smaller grain sizes are always observed for y=2 compared to y=0 for fixed x. Small-angle x-ray scattering is also used to study the grain size and this method yields sizes in the range from 3 to 7 nm, consistently almost a factor of 2 smaller than those from the XRD line broadening. This discrepancy is attributed to the difference in the regions of the 20-{mu}m-thick ribbons probed by the two methods. {copyright} {ital 1997 American Institute of Physics.}« less
  • Highlights: • Glassy Ce{sub x}La{sub 1−x}O{sub y} nanostructure films were grown on Si(1 0 0) substrate using the sol–gel method. • G{sub p} = ωϵ{sub 0}ϵ′ tan(δ) was calculated at different temperatures. • Electrical and structural the Ce{sub x}La{sub 1−x}O{sub y} samples were studied. • The conductivity-temperature study shows that the compound obeys the Arrhenius law. - Abstract: The Ce{sub x}La{sub 1−x}O{sub y} samples are synthesized, characterized and their electrical properties are reported at different molar ratios in the frequency range of 10{sup −1}–10{sup +5} Hz. Ac conductivity and permittivity data are analyzed by using conductivity formalism. The values ofmore » capacitance and tan(δ) were recorded with respect to different frequencies and temperatures. X-ray diffraction (XRD) patterns of the films show that the films posses crystalline phases. Surface morphology of the films is analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) analyses reveal that elemental composition is in right stoichiometry. Electrical characterizations of the Ce{sub x}La{sub 1−x}O{sub y} samples were done by capacitance–voltage (C–V) and current density–voltage (J–V) measurements of MOS structures. Investigation showed high value of k = 44.80 and low leakage current (∼1 × 10{sup −5} A/cm{sup 2}) of the Ce{sub 0.4}La{sub 0.6}O{sub y} film.« less
  • The use of a thin (Ni{sub 0.81}Fe{sub 0.19}){sub 1{minus}x}Cr{sub x} seed layer for obtaining high anisotropic magnetoresistance in Permalloy (Ni{sub 0.81}Fe{sub 0.19}) films is reported. The process yields a high {Delta} R/R of, for example, 3.2% for 120-{angstrom}-thick NiFe, without high-temperature deposition or annealing. X-ray diffraction shows that the NiFeCr seed layer causes the formation of large (111) textured grains in the Permalloy film, and that the interface between these two layers is quite smooth. These both increase the {Delta} R and reduce the resistance R in the film, which lead to the high {Delta} R/R. Also discussed is themore » enhanced {Delta} R/R and thermal stability trilayer magnetoresistive sensors using this NiFeCr instead of Ta as a spacer.« less