Magnetosynthesis effect on the structure and ground state of Cu${}^{2+}$-based antiferromagnets

Abstract

Subtle synthetic variables can have an outsizes influence on the crystal structure and magnetic properties of a material, particularly those of quantum materials. In this work, we investigate the impact of synthesis under a magnetic field (magnetosynthesis) on the crystal structure and magnetic properties of several Cu${}^{2+}$ ($S=1/2$) based materials with antiferromagnetic interactions and varying levels of magnetic frustration, from simple antiferromagnets to a quantum spin liquid. We employ small (0.09 - 0.37 T) magnetic fields applied during low-temperature hydrothermal or evaporative synthesis of the simple antiferromagnet CuCl${}_2\cdot$2H${}_2$O, the canted antiferromagnet (Cu,Zn)${}_3$Cl${}_4$(OH)${}_2\cdot$2H${}_2$O, the frustrated and canted antiferromagnet atacamite Cu${}_2$(OH)${}_3$Cl, and the highly frustrated quantum spin liquid herbertsmithite Cu${}_3$Zn(OH)${}_6$Cl${}_2$. We found that (Cu,Zn)${}_3$Cl${}_4$(OH)${}_2\cdot$2H${}_2$O experiences structural changes well above its magnetic transition. Atacamite Cu${}_2$(OH)${}_3$Cl synthesized under a 0.19 T field experiences a 0.15 K (~3%) decrease in its Néel transition temperature and a significant strengthening of its antiferromagnetic interactions, suggesting that magnetosynthesis can influence the ground state of moderately frustrated materials.

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