Dynamic magnetic hysteresis in single-domain particles with uniaxial anisotropy

2010 ◽  
Vol 82 (17) ◽  
Author(s):  
I. S. Poperechny ◽  
Yu. L. Raikher ◽  
V. I. Stepanov
Keyword(s):  
Magnetic Hysteresis ◽  
Uniaxial Anisotropy ◽  
Single Domain

Tunable Magnetic and Mechanical Properties in Metal Ceramic Composite Thin Films

2001 ◽  
Author(s):  
D. Kumar ◽  
J. Sankar ◽  
J. Narayan ◽  
A. Kvit
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Magnetic Properties ◽  
Smart Materials ◽  
Quantum Interference ◽  
Composite Structures ◽  
Magnetic Hysteresis ◽  
Single Domain ◽  
Blocking Temperature ◽  
Research Activities

Abstract Presently a wide spread of research activities is pursued in the area of theoretical, computational and experimental aspects of vibration studies in laminated composite structures with embedded or surface bonded smart layers in order to improve the performance of components in aerospace, mechanical, robotics, and electronic equipments. The key to the successful fabrication of these components with improved properties is the development of smart materials by materials engineering and understanding the fundamentals of materials science. It is in this context that we have developed a novel smart thin film processing method based upon pulsed laser deposition to process nanocrystalline materials with accurate size and interface control with improved mechanical and magnetic properties. Using this method, single domain nanocrystalline Fe and Ni particles in 5–10 nm size range embedded in amorphous as well as crystalline alumina have been produced. By controlling the size distribution in confined layers, it was possible to tune the magnetic properties from superparamagnetic to ferromagnetic in a controlled way. Magnetization measurements of these thin film composites as function of field and temperature were carried out using a superconducting quantum interference device (SQUID) magnetometer. Magnetic hysteresis characteristics below the blocking temperature are consistent with single-domain behavior. Mechanical properties were measured using nano-indentation measurements. The hardness of the Fe and Ni-Al2O3 nanocomposites was found to vary strongly with the size do Fe and Ni nanodots in the alumina matrix. For example, the hardness of Fe-Al2O3 system increased from 15 GPa to 28 GPa when the size of Fe dots in alumina was increased from 5 nm to 9 nm. It is envisioned that this types of smart films can be used in magnetic recording, ferrofluid technology, magnetocaloric refrigeration, biomedicine, biotechnology, aerospace applications where hard and wear-resistant coatings are also very important for its survival.

scholarly journals Pressure effect on magnetic hysteresis parameters of single-domain magnetite contained in natural plagioclase crystal

2015 ◽  
Vol 202 (1) ◽  
pp. 394-401 ◽  
Author(s):  
Masahiko Sato ◽  
Yuhji Yamamoto ◽  
Takashi Nishioka ◽  
Kazuto Kodama ◽  
Nobutatsu Mochizuki ◽  
...  
Keyword(s):  
Pressure Effect ◽  
Magnetic Hysteresis ◽  
Single Domain ◽  
Plagioclase Crystal

scholarly journals In-Plane Current Induced Nonlinear Magnetoelectric Effects In Single Crystal Films of Barium Hexaferrite

2021 ◽  
Author(s):  
Maksym Popov ◽  
Igor Zavislyak ◽  
Hongwei Qu ◽  
A. M. Balbashov ◽  
M. R. Page ◽  
...  
Keyword(s):  
Electric Power ◽  
Uniaxial Anisotropy ◽  
Barium Hexaferrite ◽  
Anisotropy Field ◽  
Current Data ◽  
Single Domain ◽  
Magnetoelectric Effects ◽  
Hexagonal Axis ◽  
Crystal Films ◽  
Device Applications

Abstract This report is on the observation and analysis of nonlinear magnetoelectric effects (NLME) for in-plane currents perpendicularly to the hexagonal axis in single crystals and liquid phase epitaxy grown thin films of barium hexaferrite. Measurements involved tuning of ferromagnetic resonance (FMR) at 56-58 GHz in the multidomain and single domain states in the ferrite by applying a current. Data on the shift in the resonance frequency with input electric power was utilized to estimate the variations in the magnetic parameter that showed a linear dependence on the input electric power. The NLME tensor coefficients were determined form the estimated changes in the magnetization and uniaxial anisotropy field. The estimated NLME coefficients for in-plane currents are shown to be much higher than for currents flowing along the hexagonal axis. Although the frequency shift of FMR was higher for the single domain resonance, the multi-domain configuration is preferable for device applications since it eliminates the need for a large bias magnetic field. Thus, multidomain resonance with current in the basal plane is favorable for use in electrically tunable miniature, ferrite microwave signal processing devices requiring low operating power.

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