Title: High-Throughput Differential Thermal Analysis for Accelerating the Development of Single Crystal Synthesis Routes
Authors: Nathan Soland, Peter Klavins, and Valentin Taufour
Abstract: Differential thermal analysis (DTA) is a useful technique for characterizing phase transitions in mixtures of chemicals. This method compares heating and cooling rates of a sample compared to an inert reference material to detect discrepancies, which indicate phase transitions. However, commercial DTA devices are expensive and only run one chemical composition at a time, which slows down the determination of multiple compositions. Material discovery requires us to grow single crystals of varying compositions, and these may require different synthesis routes, each determined individually. Phase diagrams provide information about crystallization conditions. It would be ideal if many samples could be tested simultaneously in order to greatly accelerate the trial-and-error process of novel crystal growth. This project explores the conversion of a tube furnace and an array of thermocouples connected to a single datalogger to achieve high-throughput DTA at a fraction of the cost of commercial devices. The test system of a mixture of Bi and Mn is used to demonstrate the detection of the crystallization temperature of α-MnBi across varying atomic compositions. Seven Bi-Mn mixtures of various compositions were sealed in inert atmosphere ampoules and DTA was performed to identify phase transitions in order to generate a phase diagram.