Anisotropic electron spin resonance of Y bIr₂Si₂

Abstract

A series of electron spin resonance (ESR) experiments were performed on a single crystal of the heavy fermion metal Y bIr₂Si₂ to map out the anisotropy of the ESR-intensity I(ESR) which is governed by the microwave field component of the g-factor. The temperature dependencies of I(ESR)(T) and g(T) were measured for different orientations and compared within the range 2.6 K ≤ T ≤ 16 K. The analysis of the intensity dependence on the crystal orientation with respect to both the direction of the microwave field and the static magnetic field revealed remarkable features: the intensity variation with respect to the direction of the microwave field was found to be one order of magnitude smaller than expected from the g-factor anisotropy. Furthermore, we observed a weak basal plane anisotropy of the ESR parameters which we interpret to be an intrinsic sample property.

Anisotropic Zeeman Splitting in YbNi4P2

“…The extracted strong anisotropy of the effective g-factor suggests a correlated electronic band structure in which the Yb f state in the anisotropic crystal field ground state hybridizes with the conduction electrons. This is similar to other Yb heavy-fermion systems [21,22]. We find indications for the orientation of the neck-type LTs at B 3 , B 4 , B 7 , and B 8 to form close to the (001) direction in k-space.…”

Magnetic properties and spin kinetics of a heavy-fermion Kondo lattice

“…Similar results were obtained later for 2 2 YbIr Si [6,7], and the main features of the ESR phenomenon were confirmed for 2 2 YbRh Si at very high frequencies up to 360 GHz [8]. This discovery stimulated considerable efforts, both theoretical and experimental, in order to understand the nature of the ESR existence and Kondo lattice systems in general.…”

“…I I η   The upper and lower graphs show the corresponding linewidth H ∆ and the g factor , g ⊥ respectively. Details on the intensity determination are given in [7].…”

Electron spin resonance of the ferromagnetic Kondo lattice CeRuPO

“…This procedure has successfully been applied, for instance, for the uniaxial ferromagnet CrBr 3 and indicates that the ESR in concentrated systems probes a collective mode of the coupled spin system, in contrast to dilute systems where the resonance field is determined entirely by single-ion properties. For YbRh 2 Si 2 and YbIr 2 Si 2 the data could be well described by the following relations being valid if the magnetization is proportional to the applied field ("low-field limit") [19,20]: Here, g 0 ,⊥ belong to the microscopic g-tensor, and χ ,⊥ denotes the susceptibility for H c and H⊥c. The application of these relations to the ESR of CeRuPO yields reasonable results for the 9.4 GHz measurements as can be seen by the dashed lines in figure 4.…”