Order and disorder in Ni-Pt single crystals
2011 (English)Conference paper (Refereed)
Single crystals of Ni-25.6 at.% Pt and Ni-87.8 at.% Pt were investigated by diffuse x-ray scattering for states of thermal equilibrium (923 K and 603 K, respectively). The separated short-range order scattering showed local maxima at 100 positions. Effective pair interaction parameters, as determined by the inverse Monte Carlo method, show a strong composition dependence of the nearest-neighbor interaction parameter. First-principles calculations are consistent with this finding and reveal a large contribution due to lattice strain. Based on values of the ordering energy, NiPt3 with L1 2 structure was considered as a plausible new intermetallic phase, with Monte Carlo simulations giving an order-disorder transition temperature of 650 K. A single crystal of Ni-75.2 at.% Pt, quenched from 1073 K and aged at 613 K, showed L12-type ordering, reaching a long-range order parameter of 0.50(4) after 800 h.
Place, publisher, year, edition, pages
2011. 593-601 p.
, Solid State Phenomena, ISSN 10120394
Diffuse scattering, Interaction parameters, Short-range order, Superstructures, Composition dependence, Diffuse X-ray scattering, First-principles calculation, Intermetallic phase, Inverse Monte Carlo method, Lattice strain, Local maximum, Long-range order parameters, Monte Carlo Simulation, Nearest-neighbor interactions, Order and disorder, Order-disorder transition temperature, Ordering energies, Pair interactions, Short range orders, Thermal equilibriums, Calculations, Computer simulation, Crystal structure, Diffractive optics, Intermetallics, Monte Carlo methods, Phase transitions, Platinum, Scattering, X ray scattering, Single crystals
IdentifiersURN: urn:nbn:se:kth:diva-151163DOI: 10.4028/www.scientific.net/SSP.172-174.593ISI: 000303359700092ScopusID: 2-s2.0-79960914960ISBN: 9783037851432OAI: oai:DiVA.org:kth-151163DiVA: diva2:747713
International Conference on Solid-Solid Phase Transformations in Inorganic Materials, PTM 2010; Avignon; France; 6-11 June 2010
QC 201409172014-09-172014-09-152014-09-17Bibliographically approved