Morphological stability of a planar interface subject to rapid quenching

• Published in: Journal of crystal growth Vol. 186; no. 1; pp. 291 - 297
• Main Authors: Ludwig, A., Greven, K., Sahm, P.R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.1998; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Linear-stability analysis; Materials science; Methods of crystal growth; physics of crystal growth; Morphological stability; Physics; Rapid quenching; Solid-fluid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Morphological stability; Rapid quenching; Linear-stability analysis; Crystal growth; Liquid solid interface; Planar interface; Morphology; Growth interface; Theoretical study; Instability; Linear stability; Solutes; Concentration distribution; Solidification; Quenching
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(97)00447-8

Rapid quenching of a solid–liquid interface is a common method of investigating solidification morphologies and the distribution of solute during crystallisation. As the destabilisation of the interface needs a certain but up to now unknown time interval, the quantities finally observed might change during the quenching process. In this paper the destabilisation of a planar interface with respect to a suddenly acting cooling rate is investigated. A linear stability analysis is performed considering the time-dependent concentration profile in front of an infinitesimal perturbed planar front, as superposition of the base state and a perturbation. Both profiles are estimated numerically. The time interval necessary for destabilisation is calculated as a function of wavelength. A comparison with the predictions of the analysis of Sekerka and Coriell (and Mullins and Sekerka) using the instantaneous value of the concentration gradient and solidification velocity is performed.