Paper Title:
Atomic Migration in Bulk and Thin Film L10 Alloys: Experiments and Molecular Dynamics Simulations
  Abstract

Ferromagnetic L10 ordered alloys are extensively studied nowadays as good candidates for high density magnetic storage media due to their high magnetic anisotropy, related to their chemical order anisotropy. Epitaxial thin bilayers NiPt/FePt/MgO(001) have been grown at 700 K and annealed at 800 K and 900 K. At 800 K, the L10 long-range order increases without measurable interdiffusion. At 900 K, the interdiffusion takes place without destroying the L10 long-range order. This surprising observation can be explained by different diffusion mechanisms that are energetically compared using molecular dynamics simulations in CoPt in the second moment tight binding approximation. In addition, the frequencies of the normal modes of vibration have been measured in FePd, CoPt and FePt single crystals using inelastic neutron scattering. The measurements were performed in the L10 ordered structure at 300 K. From a Born-von Karman fit, we have calculated the phonon densities of states. The migration energies in the 3 systems have been estimated using the model developed by Schober et al. (1981). The phonon densities of states have also been used to calculate several thermodynamic quantities as the vibration entropy and the Debye temperature.

  Info
Periodical
Edited by
J. Čermák and I. Stloukal
Pages
41-50
DOI
10.4028/www.scientific.net/DDF.263.41
Citation
V. Pierron-Bohnes, R.V.P. Montsouka, C. Goyhenex, T. Mehaddene, L. Messad, H. Bouzar, H. Numakura, K. Tanaka, B. Hennion, "Atomic Migration in Bulk and Thin Film L10 Alloys: Experiments and Molecular Dynamics Simulations", Defect and Diffusion Forum, Vol. 263, pp. 41-50, 2007
Online since
March 2007
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Sin Liang Ou, Po Cheng Kuo, Don Yau Chiang, Chin Yen Yeh, Shih Hsien Ma, Wei Tai Tang
Abstract:GeCu(6 nm)/Si(6 nm) bilayer recording thin film was deposited on nature oxidized silicon wafer and polycarbonate substrate by magnetron...
687
Authors: Li Li Tang, Chun Bo Wang
Chapter 2: Powder Metallurgy and Ceramic Forming
Abstract:We focus on the annealing-induced changes of N-centered nearest-neighbor (NN) entironment in Ga1-xlnxNyAs1-y quaternary alloys and present a...
768
Authors: Guido Roma, Fabien Bruneval, Li Ao Ting, Olga Natalia Bedoya Martínez, Jean Paul Crocombette
Plenary
Abstract:We present here an overview of native point defects calculations in silicon carbide using Density Functional Theory, focusing on defects...
11
Authors: Kenji Kakiage, Shiho Ishiuchi, Toru Kyomen, Minoru Hanaya
Chapter 1: Material Science
Abstract:Transparent thin films of strontium titanate (SrTiO3) were formed on the substrate of quartz glass plate by RF magnetron...
40
Authors: Maaouia Souissi, Ryusuke Nakamura, Hiroshi Numakura
Chapter 3: Defects, Stresses and Relaxation
Abstract:To verify the assumption that the anelastic relaxation effect observed in Ni3Al is due to stress-induced reorientation of antisite...
101