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In Situ Detection of Nucleation in High‐Temperature Solutions
Author(s) -
Schneider Andreas G. F.,
Sass Paul,
Schöndube Robert,
Jesche Anton
Publication year - 2020
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201900109
Subject(s) - liquidus , solidus , nucleation , crucible (geodemography) , phase transition , electrical resistivity and conductivity , materials science , phase (matter) , crystal growth , thermodynamics , phase diagram , temperature measurement , chemistry , metallurgy , physics , computational chemistry , organic chemistry , alloy , engineering , electrical engineering
The state of a sample during crystal growth from high‐temperature solutions is not accessible in conventional furnace systems. An optimization of the growth parameters often requires arduous trial and error procedures, in particular, in the case of novel multicomponent systems with unknown phase diagrams. Here a measurement technique based on lock‐in amplification is presented that allows for in situ detection of the liquidus and solidus temperatures as well as structural phase transitions. A thin, metallic measurement wire is mounted in close vicinity to the melt. Characteristic anomalies in the time‐dependent electrical resistivity of this wire allow for the detection of latent heat release without using a reference crucible. The method is implemented in a “feedback furnace” and enables an adjustment of the temperature profile based on the occurrence or absence of phase transitions. The absolute temperature serves as an additional source of information. Obtained phase transition temperatures are in good agreement with differential thermal analysis.