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

Title: Investigation of room temperature ferromagnetic nanoparticles of Gd 5Si 4

Abstract

Gd 5(Si xGe 1-x) 4 compounds undergo first-order phase transitions close to room temperature when x ~ = 0.5, which are accompanied by extreme changes of properties. We report the fabrication of the nanoparticles of one of the parent compounds-Gd 5Si 4-using high-energy ball milling. Crystal structure, microstructure, and magnetic properties have been investigated. Particles agglomerate at long milling times, and the particles that are milled >20 min lose crystallinity and no longer undergo magnetic phase transition close to 340 K, which is present in a bulk material. The samples milled for >20 min exhibit a slightly increased coercivity. As a result, magnetization at a high temperature of 275K decreases with the increase in the milling time.

Authors:
 [1];  [2];  [3];  [1];  [3]
  1. Iowa State Univ., Ames, IA (United States); Ames Lab., Ames, IA (United States)
  2. Ames Lab., Ames, IA (United States)
  3. Iowa State Univ., Ames, IA (United States)
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1227400
Report Number(s):
IS-J-8668
Journal ID: ISSN 0018-9464; PII: S0368204814001571
Grant/Contract Number:
CSR-KN/CRS-22; AC02-07CH11358
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
IEEE Transactions on Magnetics
Additional Journal Information:
Journal Volume: 51; Journal Issue: 11; Journal ID: ISSN 0018-9464
Publisher:
Institute of Electrical and Electronics Engineers. Magnetics Group
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; contrast agents; gadolinium nanoparticles; magnetocaloric nanoparticles; room temperature ferromagnetic nanoparticles

Citation Formats

Hadimani, R. L., Gupta, S., Harstad, S. M., Pecharsky, V. K., and Jiles, D. C. Investigation of room temperature ferromagnetic nanoparticles of Gd5Si4. United States: N. p., 2015. Web. doi:10.1109/TMAG.2015.2446774.
Hadimani, R. L., Gupta, S., Harstad, S. M., Pecharsky, V. K., & Jiles, D. C. Investigation of room temperature ferromagnetic nanoparticles of Gd5Si4. United States. doi:10.1109/TMAG.2015.2446774.
Hadimani, R. L., Gupta, S., Harstad, S. M., Pecharsky, V. K., and Jiles, D. C. Mon . "Investigation of room temperature ferromagnetic nanoparticles of Gd5Si4". United States. doi:10.1109/TMAG.2015.2446774. https://www.osti.gov/servlets/purl/1227400.
@article{osti_1227400,
title = {Investigation of room temperature ferromagnetic nanoparticles of Gd5Si4},
author = {Hadimani, R. L. and Gupta, S. and Harstad, S. M. and Pecharsky, V. K. and Jiles, D. C.},
abstractNote = {Gd5(SixGe1-x)4 compounds undergo first-order phase transitions close to room temperature when x ~ = 0.5, which are accompanied by extreme changes of properties. We report the fabrication of the nanoparticles of one of the parent compounds-Gd5Si4-using high-energy ball milling. Crystal structure, microstructure, and magnetic properties have been investigated. Particles agglomerate at long milling times, and the particles that are milled >20 min lose crystallinity and no longer undergo magnetic phase transition close to 340 K, which is present in a bulk material. The samples milled for >20 min exhibit a slightly increased coercivity. As a result, magnetization at a high temperature of 275K decreases with the increase in the milling time.},
doi = {10.1109/TMAG.2015.2446774},
journal = {IEEE Transactions on Magnetics},
number = 11,
volume = 51,
place = {United States},
year = {Mon Jul 06 00:00:00 EDT 2015},
month = {Mon Jul 06 00:00:00 EDT 2015}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 3works
Citation information provided by
Web of Science

Save / Share:
  • Self-polarized Gd5Si4-polyvinylidene fluoride (PVDF) nanocomposite films have been synthesized via a facile phase-inversion technique. For the 5 wt% Gd 5Si 4-PVDF films, the enhancement of the piezoelectric β-phase and crystallinity are confirmed using Fourier transform infrared (FTIR) spectroscopy (phase fraction, FβFβ, of 81% as compared to 49% for pristine PVDF) and differential scanning calorimetry (crystallinity, ΔXcΔXc, of 58% as compared to 46% for pristine PVDF), respectively. The Gd5Si4 magnetic nanoparticles, prepared using high-energy ball milling were characterized using Dynamic Light Scattering and Vibrating Sample Magnetometry (VSM) to reveal a particle size of ~470 nm with a high magnetization of 11more » emu/g. The VSM analysis of free-standing Gd5Si4-PVDF films revealed that while the pristine PVDF membrane shows weak diamagnetic behavior, the Gd5Si4-PVDF films loaded at 2.5 wt% and 5 wt% Gd 5Si 4 show enhanced ferromagnetic behavior with paramagnetic contribution from Gd5Si3 phase. The interfacial interactions between Gd5Si4 and PVDF results in the preferential crystallization of the β-phase as confirmed via the shift in the CH 2 asymmetric and symmetric stretching vibrations in the FTIR. These results confirm the magnetic Gd 5Si 4 nanoparticles embedded in the PVDF membrane lead to an increased β-phase fraction, which paves the way for future efficient energy harvesting applications using a combination of magnetic and piezoelectric effects.« less
    Cited by 1
  • Self-polarized Gd5Si4-polyvinylidene fluoride (PVDF) nanocomposite films have been synthesized via a facile phase-inversion technique. For the 5 wt% Gd 5Si 4-PVDF films, the enhancement of the piezoelectric β-phase and crystallinity are confirmed using Fourier transform infrared (FTIR) spectroscopy (phase fraction, FβFβ, of 81% as compared to 49% for pristine PVDF) and differential scanning calorimetry (crystallinity, ΔXcΔXc, of 58% as compared to 46% for pristine PVDF), respectively. The Gd5Si4 magnetic nanoparticles, prepared using high-energy ball milling were characterized using Dynamic Light Scattering and Vibrating Sample Magnetometry (VSM) to reveal a particle size of ~470 nm with a high magnetization of 11more » emu/g. The VSM analysis of free-standing Gd5Si4-PVDF films revealed that while the pristine PVDF membrane shows weak diamagnetic behavior, the Gd5Si4-PVDF films loaded at 2.5 wt% and 5 wt% Gd 5Si 4 show enhanced ferromagnetic behavior with paramagnetic contribution from Gd5Si3 phase. The interfacial interactions between Gd5Si4 and PVDF results in the preferential crystallization of the β-phase as confirmed via the shift in the CH 2 asymmetric and symmetric stretching vibrations in the FTIR. These results confirm the magnetic Gd 5Si 4 nanoparticles embedded in the PVDF membrane lead to an increased β-phase fraction, which paves the way for future efficient energy harvesting applications using a combination of magnetic and piezoelectric effects.« less
  • Cited by 1
  • Gd{sub 5}Si{sub 4}, Gd{sub 5}Ge{sub 4}, and Gd{sub 5.09}Ge{sub 2.03}Si{sub 1.88} compounds were studied by electron spin resonance. The arc-melted samples were initially characterized by optical metallography, x-ray diffraction, and static magnetization measurements. The electron spin resonance results show a negative paramagnetic g shift for Gd{sub 5}Si{sub 4} and Gd{sub 5.09}Ge{sub 2.03}Si{sub 1.88}, and a smaller positive one for Gd{sub 5}Ge{sub 4}. The values of the exchange parameter (j) between the localized Gd-4f spins and the conduction electrons are obtained from the g shifts. These values are positive and of the same order of magnitude for Gd{sub 5}Si{sub 4} andmore » Gd{sub 5.09}Ge{sub 2.03}Si{sub 1.88}, and negative one order of magnitude smaller for Gd{sub 5}Ge{sub 4}. The electron spin resonance data were interpreted considering the strongly bottlenecked solution of the coupled Bloch-Hasegawa equations.« less
  • Gd 5(Si xGe 1–x) 4 has mixed phases in the composition range 0.32 < x < 0.41, which have not been widely studied. In this paper, we have synthesized and indexed single crystal samples of Gd 5Si 1.3Ge 2.7 and Gd 5Si 1.4Ge 2.6. In this study, we have investigated the first order and second order phase transition temperatures of these samples using magnetic moment vs. temperature and magnetic moment vs. magnetic field at different temperatures. We have used a modified Arrott plot technique that was developed and reported by us previously to determine the “hidden” second order phase transitionmore » temperature of the orthorhombic II phase.« less