Interplay between External High Pressure and Intrinsic Jahn–Teller Effect in the Compression Behavior of Clinoatacamite

Abstract

Clinoatacamite (γ-Cu 2 (OH) 3 Cl) possesses a geometrically frustrated kagome lattice for the S = 1/2 antiferromagnetic spin system. Thus, it is deemed as the mother compound of many promising quantum spin liquid materials. Here, we synthesized clinoatacamite consisting of homogeneous octahedronlike particles with an average size of 1−2 μm via a hydrothermal strategy. Clinoatacamite crystallizes in a monoclinic lattice composed of Jahn−Teller distorted Cu(OH) 6 and Cu(OH) 4 Cl 2 octahedrons. The bonding nature of clinoatacamite is characterized using Raman scattering and FTIR absorption spectroscopies, which reveal the existence of trimeric hydrogen bonds. The magnetic measurements indicate that at temperatures below about 6 K, the magnetic response of the prepared samples is dominated by weak ferromagnetic contributions. The compression behavior is investigated by in situ high-pressure synchrotron radiation X-ray diffraction and Raman scattering spectroscopy. An isostructural phase transition is observed at about 8.4 GPa, which is evidenced by the anomalies in the variation curves of the lattice parameters and Raman scattering frequencies with pressure. The occurrence of the isostructural phase transition is attributed to the competition and cooperation of the external pressure and intrinsic Jahn−Teller effect, together with the interplay of intrastructural hydrogen bonding.

The pressure response of Jahn–Teller-distorted Prussian blue analogues

“…A soft c -axis is typical for compounds with a JT distortion along c , as the long axis is more compressible than the perpendicular equatorial plane. 17,51,52 Overall, the compressibilities for CuPt· n H 2 O and CuPt are identical within error to previously obtained values, 31 and hydration does not significantly influence the mechanical properties of CuPt.…”

Structural phase transformation of quantum spin liquid herbertsmithite via pressure induced enhancement of the cooperative Jahn–Teller effect and antisite disorder

“…Several additional weak peaks emerged, indicating the onset of a structural phase transition. According to some distinguishing features previously reported in the high pressure studies on clinoatacamite, 36 the high-pressure phase could be assigned to the clinoatacamite-like structure in a lower symmetry with space group P2 1 /n. The shoulder peaks, as one of the characteristics of clinoatacamite, could be indexed as (À101) and (011).…”

“…The growth habit was similar to the clinoatacamite crystallites prepared by a similar hydrothermal process. 36 The formation of the octahedron can be attributed to the difference in the development of the (101) crystalline faces due to specific local hydrodynamic conditions 37 in the reaction chamber.…”

Corrosion Behaviors of Artificial Chloride Patina for Studying Bronze Sculpture Corrosion in Marine Environments

“…Thermodynamic data suggest that the most stable polymorph is clinoatacamite. Clinoatacamite is the final product, while the other phase is intermediate [35,43,44]. Corrosion behavior is accompanied by a volume expansion of the corrosion products within the corrosion layer, which is commonly known as bronze disease.…”