Bhatia–Thornton fluctuations, transport and ordering in partially ordered Al–Cu alloys

Abstract

Abstract The Bhatia–Thornton (BT) correlation functions namely the number–number, concentration–concentration and number-concentration correlation functions in liquid binary melts are important parameters for understanding the complexities in binary liquids. In this paper, the microscopic BT correlation functions of liquid Al–Cu alloys are investigated using square well (SW) potential under mean spherical model approximation. These correlation functions are linearly related to the Ashcroft–Langreth type partial structure factors. Thermodynamically important microscopic function i.e. concentration–concentration correlation function in the long-wavelength limit, S CC (0) is analytically calculated, which is well-known in BT formalism and is often used to characterized the mixing behavior in binary melts. The Warren–Cowley chemical short range order parameters, as function of Cu concentration is also computed in the liquid Al–Cu alloys through structural studies in the long wavelength limit, which gives valuable information regarding ordering in melts. The compound forming behavior in Al–Cu alloys is evidenced by the results obtained for the value of S CC (0) and . Further, transport properties in binary mixture have been determined by using BT-correlation functions and its long wavelength limit values. Kinetic as well as thermodynamic factors were taken care in the computation of dynamic properties of alloys.