Resonance properties of the quasi-one-dimensional Ising magnet [(CH3)3NH]CoCl3⋅2H2O in the paramagnetic and magnetically ordered phases

Abstract

A study is made of the angular, frequency–field, and temperature dependences of the magnetic resonance of the quasi-one-dimensional Ising magnet [(CH3)3NH]CoCl3⋅2H2O in the paramagnetic phase. The experimental results obtained are explained in a model of spin-cluster resonance in a strongly exchange-coupled spin chain. The frequency–field dependences of the ferromagnetic resonance spectrum measured below the Néel temperature are studied for magnetic-field directions along the crystallographic axes a, b, and c. It is shown that for H→0 the spin-wave spectrum of this quasiferromagnet has two gaps (ν1=70.1 GHz and ν2=52.5 GHz).

Relaxation in the 3D ordered CoTAC spin chain by quantum nucleation of 0D domain walls

“…Recently, we have reported the observation of resonant QTM in a three-dimensional (3D) ordered system, [(CH 3 ) 3 NH]CoCl 3 •2H 2 O (CoTAC) [3]. CoTAC is a 3D network of exchange-coupled ferromagnetic chains which orders antiferromagnetically below 4.15 K [4][5][6][7] (See Figure 1). The magnetic structure is shown in the right hand side of Figure 1: The ferromagnetic Co chains run along the b axis.…”