Probing the magnetic phases in the Ni-V alloy close to the disordered ferromagnetic quantum critical point with μSR

13th International Conference on Muon Spin Rotation, Relaxation and Resonance

Schroeder, A.^1 ; Wang, R.^1 ; Baker, P.J.^2 ; Pratt, F.L.^2 ; Blundell, S.J.^3 ; Lancaster, T.^3,4 ; Franke, I.^3 ; Möller, J.S.^3

Department of Physics, Kent State University, Kent

OH

44242, United States^1

ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford

OX11 0QX, United Kingdom^2

Oxford University Department of Physics, Clarendon Laboratory, Parks Road, Oxford

OX1 3PU, United Kingdom^3

Durham University, Centre for Materials Physics, South Road, Durham

DH1 3LE, United Kingdom^4

关键词: Field distribution;    Longitudinal fields;    Low temperatures;    Magnetic inhomogeneities;    Muon spin relaxation;    Precession frequency;    Quantum critical points;    Vanadium concentration;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/551/1/012003/pdf
DOI  :  10.1088/1742-6596/551/1/012003

来源: IOP

【 摘 要 】

Zero (ZF) and longitudinal field (LF) muon spin relaxation data of the d-metal alloy Ni1-xVx are presented at several vanadium concentrations x below and above the critical xc 11 % where long-range ferromagnetic (FM) order is suppressed. The clear single precession frequency observed for Ni, as expected for a homogeneous FM, changes to rather damped osciallation with small V substitution at x 4 %, confirming magnetic inhomogeneities caused by the less magnetic V environments in the magnetic Ni matrix. Furthermore, local fields and spatial field distributions can be estimated to characterize different inhomogeneous regimes developing with x in the FM phase of Ni1-xVx. In the regime of x 7-10 % a Kubo Toyabe function well describes the low temperature ZF and LF asymmetry data supporting a static Gaussian field distribution. Closer to the quantum critical concentration a single scale static Kubo Toyabe function with one field distribution is not sufficient to describe the muon relaxation. These data indicate that further changes in spatial distributions and dynamics are evolving as expected within the critical regime of a disordered quantum critical point.