Metastable microheterogeneity of melts in the Ga–Bi system with limited solubility of components in liquid state

A set of acoustic (using the pulse phase method for ultrasound velocity v _s measurement) and γ-absorption experiments with the Ga–Bi melts have been performed to clear the nature of their microinhomogeneity. Both methods allow determining υ _s and intensity of the penetrating γ-beam, I, at various distances, h, from the bottom of the measuring cell. Distinct υ _s(h) and I(h) dependences were discovered in one phase domain of the phase diagrams. It is clear that such inhomogeneity is connected with the chemical inhomogeneity of the melt which, in its turn, can exist if one of the components forms very large particles containing 10⁴–10⁵ atoms. The cupola-like borders of the domains where such inhomogeneity exists were fitted in the phase diagrams of the systems under investigation. The inhomogeneity has been confirmed in special acoustic experiments with superposition of ultrasound and low-frequency oscillation.