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NICKEL NANOCOMPOSITE THIN FILMS Honghui Zhou, A. Kvit, D. Kumar, and J. Narayan Department of Materials Science and Engineering and NSF Center for Advanced Materials and Smart Structures. North Carolina State University, Raleigh, NC 27695-7916, U.S.A. ABSTRACT Nickel was deposited on epitaxial TiN matrix layer grown on Si (100) substrate by pulsed laser deposition process (PLD). Transmission electron microscopy (TEM) study shows that nanoparticles formed are single crystals with two kinds of epitaxial relationship with respect to matrix TiN. One is cube on cube, where (200) Ni // (200) TiN // (200) Si and (022) Ni // (022) TiN // (022) Si. The particles grown in this orientation have a trapezoidal morphology in [011] projection. The other involves a 90 ° rotation with respect to [011] direction of TiN matrix (zone axis), where (022) Ni // (200) TiN // (200) Si and (200) Ni // (022) TiN // (022) Si. The particles grown in this rotated orientation have a triangular morphology in [011] projection and a smaller lattice constant compared with that of pure nickel. The possible mechanism of forming these two epitaxial orientations is discussed. Superconducting quantum interference device (SQUID) magnetometer was used for magnetic measurements. In order to investigate the effect of texturing on magnetic properties of nanoparticles, results were compared with those obtained from Ni nanoparticles grown on amorphous Al2O3 matrix layer in previous research. It was found that both blocking temperature and coercivity of Ni nanoparticles grown on epitaxial TiN matrix are significantly higher than that of Ni grown on amorphous Al2O3. The higher value of coercivity is possibly associated with the stronger tendency of crystallographically oriented particles to retain their magnetic moments in the presence of reversing magnetic field. INTRODUCTION Nanomagnetic materials have drawn significant attention in recent years due to their dramatically improved physical properties critical for enhancing the magnetic device performance, such as giant magnetoresistance, superparamagnetism, large coercivities, high Curie temperature, and low saturation magnetization [1-7]. Magnetic properties of the nanomagnetic materials are closely related to the magnetic anisotropy of the material, which depends not only on the size, shape and strain state of the particles, but also on their crystal structure and orientation. However, so far, most studies in this area have been focused on the dependence of magnetic properties on the particle size and separation. It is expected that further improvement in these properties could be realized by texturing the magnetic particles along their easy axis. In the present study, epitaxial Ni nanoparticles were grown on TiN thin-film matrix by pulsed laser deposition (PLD) technique. The crystalline quality of the particles was investigated by conventional and high-resolution transmission electron microscopy (TEM and HRTEM). In order to investigate the effect of texturing of magnetic particles on their magnetic prop