Browsing J. Ping Liu, Ph.D. by Title
Now showing items 7-21 of 21
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Effect of thermal fluctuations on the recoil loops of SmCo5[subscript]/Fe nanocomposite system
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2009-02-13)The correlation between the recoil loop openness and the activation volume has been studied for the SmCo5/α-Fe nanocomposite powder material prepared by mechanical alloying. The α-Fe phase content in the nanocomposite ... -
Effects of particle size and composition on coercivity of Sm–Co nanoparticles prepared by surfactant-assisted ball milling
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2010-04-15)The correlation between the recoil loop openness and the activation volume has been studied for the SmCo5/α-Fe nanocomposite powder material prepared by mechanical alloying. The α-Fe phase content in the nanocomposite ... -
Fabrication of bulk nanocomposite magnets via severe plastic deformation and warm compaction,
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2010-03-10)We demonstrate that a SmCo/FeCo based hard/soft nanocomposite material can be fabricated by distributing the soft magnetic α-Fe phase particles homogeneously in a hard magnetic SmCo phase through severe plastic deformation. ... -
First-principles prediction of enhanced magnetic anisotropy in FeCo alloys
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2008-02-04)The structural, electronic, and magnetic properties of FeCo alloys were studied by first-principles calculations. It has been found that the alloys prefer chemically noncubic geometries in a wide composition range. This ... -
Grain boundary contribution to recoil loop openness of exchange-coupled nanocrystalline magnets
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2009-04-29)It has been well known that recoil loop openness is related to soft-phase presence in exchange-coupled hard-soft nanocomposite magnets. Our study on recoil loop openness of exchange-coupled nanocrystalline magnets (both ... -
High thermal stability of carbon-coated L1[subscript]0-FePt nanoparticles prepared by salt-matrix annealing
(Institute of Applied PhysicsDepartment of Physics, The University of Texas at Arlington, 2008-02-08)Monodisperse L10-FePt nanoparticles with size ranging from 3 to 8 nm were prepared by the salt-matrix annealing method. It was observed that the annealed particles have high thermal stability—no sintering occurred even ... -
Mechanism of the anomalous temperature dependence of coercivity in Sm(Co,Fe,Cu,Zr)[subscript]z high-temperature magnets
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2006-01-24)Coercivity mechanism of the precipitation-hardened Sm(Co,Fe,Cu,Zr)z high-temperature magnets was found to vary with temperature by measurements of reversible magnetization. The magnetization reversal is mainly controlled ... -
Observation of L1[subscript]0-like chemical ordering in a decahedral FePt nanoparticle by C[subscript]s-corrected high resolution transmission electron microscopy
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2009-03-09)The state of the chemical ordering in a decahedral FePt nanoparticle was studied using aberration corrected high resolution transmission electron microscopy. With the reduced image delocalization effect as a result of ... -
Phase Transformation and Magnetic Hardening in Isolated FePt Nanoparticles
(IEEEDepartment of Physics, The University of Texas at Arlington, 2009-03-31)Isolated monodisperse L1[subscript]0 FePt nanoparticles coated by carbon were obtained by adding enough surfactants that decomposed into carbon after the chemical synthesis and postannealing of the A1 FePt nanoparticles. ... -
Phase Transformation and Magnetic Hardening in Isolated FePt Nanoparticles
(IEEE XploreIEEEDepartment of Physics, The University of Texas at Arlington, 2009-07)Isolated monodisperseL10 FePt nanoparticles coated by carbon were obtained by adding enough surfactants that decomposed into carbon after the chemical synthesis and postannealing of the A1 FePt nanoparticles. The effect ... -
Rapid thermal annealing of FePt nanoparticles
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2008-07-11)We report a systematic study on rapid thermal annealing (RTA) of FePt nanoparticles. FePt particles with an average size of 8 nm were synthesized by a chemical solution method, and then annealed using RTA and conventional ... -
Shape control of FePt nanocrystals
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2009-04-06): FePt nanocrystals were prepared by simultaneous reduction of platinum acetylacetonate and thermal decomposition of iron pentacarbonyl in properly chosen solvents/surfactants. A variety of FePt nanocrystals, including ... -
Structural phase transition and ferromagnetism in monodisperse 3 nm FePt particles
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2007-08-30)FePt nanoparticles with a size of 3 nm and thermally stable room-temperature ferromagnetism are investigated. The monodisperse nanoparticles were prepared by chemical synthesis and a salt-matrix annealing technique. ... -
Temperature- and magnetic-field-induced phase transitions in Fe-rich FePt alloys
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2007-06-01)Structural and magnetic properties of the FexPt100-x (x=78–88) alloys have been investigated. It is found that for all of the investigated compositions, a phase transition occurs from the disordered γ phase to the ordered ... -
Transformation of electrical transport from variable range hopping to hard gap resistance in Zn[subscript]1−[subscript]xFe[subscript]xO[subscript]1[subscript]v magnetic semiconductor films
(American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2006-11-16)Transformation of the electrical transport from the Efros and Shklovskii [J. Phys. C 8, L49 (1975)] variable range hopping to the “hard gap” resistance was experimentally observed in a low temperature range as the Fe ...