C. B. Rong

University of Texas at Arlington, Arlington, Texas, United States

Are you C. B. Rong?

Claim your profile

Publications (10)34.83 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Nd2Fe14B/α-Fe-based hard/soft nanocomposite magnets with Co addition have been prepared by ball-milling and warm compaction. It was found that Co addition into the magnetically hard phase improves magnetic properties significantly, especially the remanence ratio and coercivity. The effect on the magnetic properties of the selective Co addition may be attributed to enhanced interdiffusion across the hard/soft interface that improves the interface conditions for effective interphase exchange coupling. By optimizing the Co content in the Nd15Fe79−xCoxB6 hard phase, an energy product value about 21 MG Oe can be obtained in the isotropic Nd2(FeCo)14B/α-(FeCo) nanocomposite magnets compared with 15 MG Oe of Nd2Fe14B/α-Fe nanocomposite magnets prepared under the same conditions with the same grain size and microstructure, owing to the strengthened intergranular exchange interactions.
    Journal of Physics D Applied Physics 12/2012; 46(4):045001. · 2.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The microstructure and compositions of the bulk nanocomposite SmCo/Fe permanent magnet were studied using transmission electron microscopy and 3-dimensional atom probe techniques. The excellent magnetic properties were related to the uniform nanocomposite structure with nanometer α-Fe particles uniformly distributed in the SmCo phase matrix. The α-Fe phase contained ∼26at% Co, and the SmCo phase contained ∼19at% Fe, confirming that the interdiffusion of Fe and Co atoms between the two phases occurred. The formation of the α-Fe(Co) phase explained why the saturation magnetization of the nanocomposite permanent magnet was higher than that expected from the original pure α-Fe and SmCo5 powders, which enhanced further the maximum energy product of the nanocomposite permanent magnet.
    Journal of Magnetism and Magnetic Materials 01/2011; 323(22):2855-2858. · 2.00 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nd–Fe–B nanoparticles have been obtained by using surfactant-assisted ball milling and subsequent size-selection technique. Structural analyses show that nanoparticles with two particle sizes around 10 and 100 nm were obtained. The partially amorphous Nd–Fe–B nanoparticles give their room-temperature coercivities around 0.1 and 1.5 kOe for the small and large nanoparticles, respectively. As the temperature decreases to 200 K, the coercive force of the large nanoparticles increases by 50% due to the enhancement of the magnetocrystalline anisotropy of the Nd2Fe14B phase in the particles.
    Journal of Applied Physics 02/2009; 105(7). · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The essence of the anomalous Hall effect (AHE) is not fully understood and it still attracts considerable attention. Magnetic and magnetotransport properties of Ce Fe <sub>1.95</sub> Al <sub>0.05</sub> compound in diverse magnetic state are studied which is helpful to know the essence of AHE. The semiempirical relation ρ<sub>xy</sub>=R<sub>0</sub>B+4πR<sub>s</sub>M , widely accepted, is valid in describing the behaviors of AHE in ferromagnetic and paramagnetic state, but invalid in antiferromagnetic state in Ce Fe <sub>1.95</sub> Al <sub>0.05</sub> compound.
    Journal of Applied Physics 05/2008; · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The magnetization reversal in very small FePt particles is investigated by analytical and numerical calculations. The modeling focuses on particles with diameters from 3 to 15 nm , as produced by a salt-matrix annealing technique. Experiment shows that the particles exhibit a certain degree of structural inhomogenity, which has a far-reaching effect on the magnetic hysteresis. In particles larger than about 10 nm , the magnetization-reversal mode is strongly inhomogeneous, and there are several scenarios that depend on the symmetry of inhomogenity. Small particles reverse nearly coherently, and the coercivity is essentially equal to the volume-averaged anisotropy. In this case, nonrectangular hysteresis loops reflect factors such as grain misalignment, particle-size distribution, and different degrees of L1<sub>0</sub> order in different particles.
    Journal of Applied Physics 05/2008; · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A comparable study of the microstructure and magnetic properties was performed for magnetite films deposited on (100)-oriented MgO and Sr Ti O <sub>3</sub> (STO) substrates. The growth of strained high quality Fe <sub>3</sub> O <sub>4</sub> films was confirmed by x-ray diffraction analysis and Raman spectroscopy measurements. The surface morphology and magnetic properties of the two films were found to be obviously different. Moreover, a stripelike magnetic domain structure was observed in the film on STO. Substrate-induced strain is believed to be responsible for these observations, which significantly affects the magnetic anisotropy and the magnetic coupling at the antiphase boundaries in the films.
    Journal of Applied Physics 05/2008; · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We report the switching behavior of resistive states induced by current flowing in La1−xCaxMnO3 films. The transport behavior upon treatments by applying a large dc current has been investigated in the absence of magnetic field. A switching from low to high resistive state was found upon applying a large dc current for the both compositions. The critical currents for the switching are 10.5 mA (density of 2.3×103 A/cm2) and 6.7 mA (density of 1.6×103 A/cm2) for compositions x = 0.2 and 0.3, respectively. Our repeated measurements indicate that the high resistive state appeared in the film x = 0.2 is much stable. Exposing the sample in air and room temperature does not cause any change of the transport properties. However, for the film with x = 0.3, the induced high resistive state behaves with unstable characteristics. Keeping the sample at a low temperature of 20 K, a relaxation to a higher resistive state takes place. The mechanism of phase separation was taken into account in the interpretation of the observed phenomena.
    Journal of Applied Physics 01/2008; 103(7):07F712-07F712-3. · 2.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report the growth of colossal magnetoresistive (CMR) films La0.7Ca0.3MnO3 (LCMO) and La0.9Ba0.1MnO3 (LBMO) onto Si (100) using a simple pulsed-laser deposition technique. To avoid oxidation of the Si surface, an initial growth of SrTiO3 of a few atomic layers was carried out. We found that epitaxial growth of LCMO and LBMO films on Si can be realized by optimizing the deposition process. The obtained LCMO and LBMO films show ferromagnetic nature and the resulted LCMO/Si and LBMO/Si heterojunctions exhibit good rectifying behavior with magnetically tunable characteristics.
    Journal of Applied Physics 01/2008; 103(7). · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Phase transition processes and magnetocaloric effect in Ni2.15Mn0.85-xCoxGa (x=0.03, 0.04, 0.05, and 0.06) alloys were investigated. The alloys exhibit nonmodulated tetragonal martensitic structure at room temperature. According to experiment results, Ni2.15Mn0.85-xCoxGa alloys undergo a magnetostructural phase transition on the heating process when electron concentration is in the range from 7.633 to 7.643. The alloys also show large magnetic entropy changes. With increasing Co content, the magnetic entropy change decreases.
    Journal of Applied Physics 01/2008; 103. · 2.21 Impact Factor
  • Source
    Advanced Materials 11/2006; 18(22):2984 - 2988. · 14.83 Impact Factor