Chemical short-range order in dense random packed models. [Ni/sub 35/Ti/sub 65/; Ni/sub 35/Zr/sub 65/]

Conference · Wed Dec 31 23:00:00 EST 1986

OSTI ID:5896375

Saw, C K; Schwarz, R B

A dense random packed model of an amorphous alloy was used to calculate the total and partial reduced radial distribution functions, the Bhathia-Thorton number-concentration fluctuations, and the number-concentration interference functions. The model was applied to amorphous Ni/sub 35/Ti/sub 65/ using atomic radii of 1.10 and 1.58 A/sup -1/ for nickel and zirconium, respectively. Chemical short-range order was included in the model by permuting nickel-zirconium nearest-neighbors atoms pairs in response to a decrease in the alloy's enthalpy. The permutations were found to decrease in the Warren-Cowley order parameter from zero to -0.38. The increase in chemical short range order is accompanied by the appearance of a peak in the partial interference function I/sub Ni-Ni/(K) at K = 1.9 A/sup -1/. The increase in chemical short range order and the prepeak in I/sub Ni-Ni/(K) are tentatively attributed to the formation of double tetrahedra with three zirconium atoms at the base and two nickel atoms at the apexes. 18 refs., 5 figs.

• Research Organization: Los Alamos National Lab., NM (USA); Hoechst Celanese Corp., Summit, NJ (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5896375
• Report Number(s): LA-UR-87-3617; CONF-8708104-4; ON: DE88001800
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOY SYSTEMS
ALLOYS
AMORPHOUS STATE
ATOMIC MODELS
ATOMIC RADII
BINARY ALLOY SYSTEMS
DISTRIBUTION FUNCTIONS
ELECTRONIC STRUCTURE
ELEMENTS
ENTHALPY
EQUATIONS
FOURIER TRANSFORMATION
FUNCTIONS
INTEGRAL TRANSFORMATIONS
INTEGRALS
MATHEMATICAL MODELS
METALS
NICKEL
NICKEL ALLOYS
ORDER PARAMETERS
PHYSICAL PROPERTIES
STRUCTURE FACTORS
THERMODYNAMIC PROPERTIES
TITANIUM ALLOYS
TRANSFORMATIONS
TRANSITION ELEMENTS
ZIRCONIUM
ZIRCONIUM ALLOYS