Abstract
A complete phase diagram of Zn-substituted quantum quasi-two-dimensional helimagnet LiCu2O2 has been presented. Helical ordering transition temperature (Th) of the original LiCu2 O 2 follows finite size scaling for less than ∼5.5% Zn substitution, which implies the existence of finite helimagnetic domains with domain boundaries formed with nearly isolated spins. Higher Zn substitution ≥5.5% quenches the long-range helical ordering and introduces an intriguing Zn-level-dependent magnetic phase transition with slight thermal hysteresis and a universal quadratic field dependence for Tc (Zn>0.055,H). The magnetic coupling constants of nearest-neighbor J1 and next-nearest-neighbor J2 (α= J2 / J1) are extracted from high temperature series expansion fitting and N=16 finite chain exact diagonalization simulation. We have also provided evidence of direct correlation between long-range helical spin ordering and the magnitude of electric polarization in this spin-driven multiferroic material.
Original language | English |
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Article number | 094450 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 82 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2010 Sept 29 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics