Thermal Analysis and X-Ray Structural Study on Phase Transitions in NH₄CsZnCl₄

Abstract

Ammonium cesium tetrachlorozincate (NH₄CsZnCl₄), one of the new ABXY ₄-type in the (NH₄)₂SO₄ family, was crystallized by evaporating the aqueous solution at room temperature. The phase transition and crystal structure were studied by means of thermogravimetric analysis, differential scanning calorimetry and single-crystal X-ray diffraction. As a result of thermal anomaly detection in the temperature range between 93 K and 473 K, anomalies corresponding to phase transitions were observed at around 216 K, 242 K and 458 K. It was also revealed that NH₄CsZnCl₄ belonged to the orthorhombic crystal system at room temperature and had lattice constants of a = 5.994(2) Å, b = 10.636(2) Å and c = 7.784(2) Å.

Keywords:

• ABXY ₄-type
• NH₄CsZnCl₄
• phase transition
• thermogravimetric analysis
• differential scanning calorimetry
• single-crystal X-ray diffraction

PACS #:

• 61.66.Fn
• 05.70Fh
• 81.70.Pg
• 61.05.cp

Acknowledgment

This research was partly funded by The Nitto Foundation and The Naito Science & Engineering Foundation.