New phase diagram of Zn-doped CuGeO3

TL;DR

This study maps the phase diagram of Zn-doped CuGeO3 using neutron scattering, revealing the persistence of the spin-Peierls phase up to 6% Zn doping and coexistence with antiferromagnetic order.

Contribution

It provides detailed neutron scattering evidence of phase transitions and coexistence in Zn-doped CuGeO3, extending understanding beyond previous susceptibility studies.

Findings

AF order confirmed for x≥0.02

SP phase persists up to 6% Zn doping

Coexistence of SP and AF states below Néel temperature

Abstract

A series of high-quality single crystals of Cu$_{1-x}$Zn$_x$GeO$_3$ have been examined by neutron scattering techniques. An antiferromagnetic (AF) ordering is confirmed for samples with $x\geq 0.02$, in complete agreement with previous reports. We show that the spin-Peierls (SP) phase transition persists to 6\% Zn, whereas previous magnetic susceptibility measurements reported a deterioration of the SP transition above 2\% Zn. We present some details of the successive transitions upon lowering temperature into the spin-Peierls phase which is followed by a transition into an antiferromagnetically ordered phase. Below the N\'eel temperature we observe the coexistence of the SP lattice dimerization and AF states.