  A pseudo ternary diffusion couple technique in a multicomponent system by
simplifying the mathematical complications of Onsager formalism is proposed for
the estimation of composition dependent values of the interdiffusion
coefficients. This is otherwise impossible following the conventional method in
a system with more than three components. Other alternative methods estimate
the average diffusion coefficients over a composition range of random choice
and lack physical significance. This method can be followed in a multicomponent
system with any number of components on the condition that only three
components develop diffusion profiles keeping others as constant.
