Title: An axial temperature profile curvature criterion for the engineering of convex crystal growth interfaces in Bridgman systems

Abstract

A unifying idea is presented for the engineering of convex melt-solid interface shapes in Bridgman crystal growth systems. Previous approaches to interface control are discussed with particular attention paid to the idea of a “booster” heater. Proceeding from the idea that a booster heater promotes a converging heat flux geometry and from the energy conservation equation, we show that a convex interface shape will naturally result when the interface is located in regions of the furnace where the axial thermal profile exhibits negative curvature, i.e., where d²T/dz² < 0. This criterion is effective in explaining prior literature results on interface control and promising for the evaluation of new furnace designs. Here we posit that the negative curvature criterion may be applicable to the characterization of growth systems via temperature measurements in an empty furnace, providing insight about the potential for achieving a convex interface shape, without growing a crystal or conducting simulations.

Authors:

Peterson, Jeffrey H. ^[1]; Derby, Jeffrey J. ^[1]

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+ Show Author Affiliations

1. University of Minnesota, Minneapolis, MN (United States)

Publication Date:

Fri Sep 30 00:00:00 EDT 2016

Research Org.:

Univ. of Minnesota, Minneapolis, MN (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1533970

Alternate Identifier(s):

OSTI ID: 1396682

Grant/Contract Number:  

NA0002514; AC02-05CH11231; NA0002514 and DE-AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Crystal Growth

Additional Journal Information:

Journal Volume: 468; Journal Issue: C; Journal ID: ISSN 0022-0248

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; heat transfer; computer simulation; directional solidification; interfaces; Bridgman technique