Microstructure and magnetic properties in percolating (Ni–Fe)x(SiO2)1–x granular films

1996 ◽  
Vol 11 (10) ◽  
pp. 2506-2517 ◽  
Author(s):  
Y. Xu ◽  
X. Yan
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Particles ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Volume Ratio ◽  
Metal Insulator ◽  
Composition Structure ◽  
Enhanced Surface ◽  
Microstructure And Magnetic Properties

We studied composition, structure, microstructure, and magnetic properties of percolating (Ni–Fe)x(SiO2)1−x granular thin films. We found that the magnetic susceptibility increases and the coercivity decreases when increasing x toward xt, the critical metallic volume fraction for the metal-insulator transition, and the susceptibility decreases and the coercivity increases when increasing annealing temperature for x just below xt. Comparison of the microstructure and the magnetic properties suggests that the enhanced magnetic susceptibility for x just below xt is probably associated with the labyrinthine structure of the granular magnetic particles where there is an enhanced surface-to-volume ratio of the magnetic particles.

scholarly journals Microstructure and magnetic properties of Nd-Fe-B-(Re, Ti) alloys

Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 29-33
Author(s):  
Mariusz Hasiak
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Volume Fraction ◽  
Magnetic Characteristics ◽  
Ti Alloys ◽  
Wide Range ◽  
Magnetically Hard ◽  
Ti Addition ◽  
Microstructure And Magnetic Properties

Abstract The microstructure and magnetic properties of nanocomposite hard magnetic Nd-Fe-B-(Re, Ti) materials with different Nd and Fe contents are studied. The role of Re and Ti addition in phase composition and volume fraction of the Nd-Fe-B phase is determined. All samples are annealed at the same temperature of 993 K for 10 min. Mössbauer spectroscopy shows that the addition of 4 at.% of Re to the Nd8Fe78B14 alloy leads to creation of an ineligible amount of the magnetically hard Nd2Fe14B phase. Moreover, the microstructure and magnetic characteristics recorded in a wide range of temperatures for the Nd8Fe79−xB13Mx (x = 4; M = Re or Ti) alloys are also analyzed.

Grain-Size Effects and the Physical Properties of La0.7Ca0.3MnO3-δ

2005 ◽  
Vol 277-279 ◽  
pp. 929-934 ◽  
Author(s):  
H.K. Lee ◽  
Horst Baier ◽  
J.S. Park ◽  
Y.P. Lee ◽  
Youn Seoung Lee
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Transition Temperature ◽  
Physical Properties ◽  
Size Effects ◽  
Annealing Temperature ◽  
Oxygen Deficiency ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Grain Sizes

The effects of grain-size in La0.7Ca0.3MnO3-δ (LCMO) system have been studied in connection with the magnetic and electronic properties. LCMO system prepared by the solid-state reaction was annealed in air at 1200, 1300 and 1400°C. The grain sizes of LCMO samples become larger with increasing of annealing temperature (TA ). The magnetization in LCMO samples increased while the coercive field decreased with increasing TA. The conductivity increased and the metal-insulator transition temperature TM-I decreased with increasing of TA. These physical properties are due to the oxygen deficiency caused by the increase of grain size. Finally, it was found that the grain size and the mechanical connection between grains play an important role in determining the electronic and magnetic properties.

Relationship between Microstructure and Magnetic Properties of Nano-Scale Particles Formed in Cu-Ni-(FeCo) Alloys

2018 ◽  
Vol 941 ◽  
pp. 1324-1329 ◽  
Author(s):  
Shintaro Matai ◽  
Hibiki Sakakura ◽  
Mahoto Takeda
Keyword(s):  
Magnetic Properties ◽  
Quantum Interference ◽  
Magnetic Particles ◽  
Superconducting Quantum Interference Device ◽  
Recording Technology ◽  
Treatment Conditions ◽  
Transmission Electron ◽  
Feco Alloys ◽  
The Relationship ◽  
Microstructure And Magnetic Properties

Numerous studies have been conducted to develop next-generation recording technology in spintronics. Because ultrafine magneitc particles are vital components of the technology, the interplay between the microsturcture and magnetic properties has attracted attention extensively in recent years. We focused on the relationship between the microstructure and magnetic properties of Cu-Ni-X (X=Fe, Co, FeCo) alloys comprising nanogranular magnetic particles. In this work, we prepared Cu-20 at% Ni-5 at% (FeCo), Cu-20 at% Ni-5 at% Fe, Cu-20 at% Ni-5 at% Co and examined the changes of microstructure and magnetic properties associated with heat treatments and composition. To examaine microstructural evolution of the alloy specimens, we conducted transmission electron microscope observations (TEM) with the as-quenched specimens and those aged at at 773-1073 K. We also carried out magneto-thermo gravimetry (MTG) measurements, superconducting quantum interference device (SQUID) measurements, magnetoresistance (MR) measurements and first-principles calculations based on the Koster-Korringa-Rostker (KKR) method with the Coherent Potential Approximation (CPA), to investigate the magnetic properties. The present work confirmed that the microstructure significantly changed, depending on the composition and heat treatment conditions. The present work also revealed that the magnetic properties closely correlated with the microstructure of samples.

Effect of Annealing Temperature on the Microstructure and Magnetic Properties of MnGa Films

2016 ◽  
Vol 29 (8) ◽  
pp. 2035-2039
Author(s):  
Weiming Cheng ◽  
Shize Jiang ◽  
Wenchao Xu ◽  
Yajuan Hui ◽  
Haiwei Wang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Annealing Temperature ◽  
Microstructure And Magnetic Properties

scholarly journals Microstructure And Magnetic Properties Of The FeZr(Y)NbCuB Amorphous Alloys

2015 ◽  
Vol 60 (2) ◽  
pp. 1071-1074 ◽  
Author(s):  
J. Gondro ◽  
K. Błoch ◽  
M. Nabiałek ◽  
K. Waltters ◽  
M. Szota
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Chemical Composition ◽  
Curie Temperature ◽  
Amorphous Alloys ◽  
X Ray ◽  
Low Field ◽  
A Minor ◽  
Structure And Microstructure ◽  
Microstructure And Magnetic Properties

Abstract In this paper, the results of investigations are presented, into the microstructure and magnetic properties of the following amorphous alloys in the as-quenched state: Fe82Zr7Nb2Cu1B8 and Fe86Zr4Y3Nb1Cu1B5. The studied material was produced in the form of thin ribbons of 3 mm width and 20 μm thickness. The structure and microstructure of the samples have been investigated by means of Mössbauer spectrometry and X-ray diffractometry. In addition, the magnetic properties of these materials have been determined, i.e. the low-field magnetic susceptibility, and the magnetisation as a function of temperature and magnetising field. On the basis of the performed investigations, it has been found that a minor change in the quantities of elements favouring amorphisation, such as: Zr and Y, has an influence on the value of the Curie temperature and the magnetic properties of the resulting alloys. It should be noticed that the changes, introduced in the chemical composition of the alloys, don’t change the combined volume of these elements, i.e. Zr7 and Zr4Y3.

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