Article ID Journal Published Year Pages File Type
1236017 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2007 5 Pages PDF
Abstract

Ni++ ions doped inorganic CuGeO3 sample has been studied by using electron spin resonance (ESR) technique in the temperature range of 3–300 K. The ESR spectrum of Cu++ ion has been observed to be strongly temperature dependent for inorganic spin-Peierls (SP) Cu0.96Ni0.04GeO3 samples. The ESR line width and ESR amplitude exponentially vanishes below a critical temperature, Tsp = 14 K. The one-dimensional (1D) antiferromagnetic (AF) spin chain formed of Cu++ is broken by Ni++ (spin-1) ion, giving uncoupled spins at the end of the chains that give extra contribution to the spectra at lower temperature and stabilizes a Néel state. The g-factor is much smaller than the expected value for isolated Cu++ and Ni++ ions and is much more anisotropic than for undoped samples [O. Yalçın, B. Aktaş, J. Magn. Magn. Mater. 258/259 (2003) 137 (reference therein)]. It is shown that the ground state of dimerized spins is singlet. The spin-flop (SF) phenomenon is obtained from AF state mixed condition and then ferromagnetic (FM) state. The spin-flop field slightly increases when increasing temperature in the temperature range 100–300 K. The SF transition is showed almost AF order for Cu0.96Ni0.04GeO3.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
Authors
, , ,