Extension of the zinc paratacamite phase diagram: Probing the effect of spin vacancies in an S=1/2 kagome antiferromagnet

作者：de Vries M A^*; Wulferding D; Lemmens P; Lord J S; Harrison A; Bonville P; Bert F; Mendels P

来源：Physical Review B, 2012, 85(1): 014422.

DOI：10.1103/PhysRevB.85.014422

We report on the extension of the phase diagram of the magnetic model system zinc paratacamite, Zn(x)Cu(4-x)(OH)(6)Cl(2) (0 <= x <= 1), with compositions x > 1, up to similar to 1.2. This amounts to diamagnetic doping of the kagome lattice of antiferromagnetically coupled Cu(2+) with S = 1/2 in what was hitherto known as the end member in the series: herbertsmithite of stoichiometry ZnCu(3)(OH)(6)Cl(2). Combining chemical analysis, x-ray diffraction, magnetic susceptibility measurements, Raman spectroscopy and muon spin relaxation spectroscopy we conclude the following: (i) Herbertsmithite can be synthesized in stoichiometric form, but it is affected by antisite disorder of similar to 7% in Cu2+ content, implying that for x = 1, similar to 7% of the Cu kagome sites is occupied by Zn(2+). (ii) The Zn content can be increased up to x similar to 1.2. No qualitatively new behavior is found for the diamagnetically doped kagome lattice, only a continuation of the trends observed for samples with x < 1 as x is increased.

• 出版日期2012-1-20
• 单位中国地震局