Muon spin rotation and relaxation study on Nb${}_{1-y}$Fe${}_{2+y}$

Abstract

We present a detailed study of the magnetic properties of weakly ferromagnetic/quantum critical Nb${}_{1-y}$Fe${}_{2+y}$ using muon spin rotation and relaxation ($\mu$SR). By means of an angular dependent study of the muon spin rotation signal in applied magnetic fields on a single crystal in the paramagnetic state we establish the muon stopping site in the crystallographic lattice of NbFe${}_2$. With this knowledge we develop models to describe the muon spin rotation and relaxation signals in the weakly ferromagnetic, spin density wave and quantum critical phases of Nb${}_{1-y}$Fe${}_{2+y}$ and fit the corresponding experimental data. In particular, we quantify the $\mu$SR response for quantum critical behavior in Nb${}_{1.0117}$Fe${}_{1.9883}$ and extract the influence of residual weak structural disorder. From our analysis, Nb${}_{1-y}$Fe${}_{2+y}$ emerges to be uniquely suited to study quantum criticality close to weak itinerant ferromagnetic order.

References in corpus (23)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Quantum phase transitions
• Non-Fermi liquid behavior and Griffiths phase in {\it f}-electron compounds
• Metallic Quantum Ferromagnets
• Influence of Generic Scale Invariance on Classical and Quantum Phase Transitions
• First order transitions and multicritical points in weak itinerant ferromagnets
• Quantum Phase Transitions in the Itinerant Ferromagnet ZrZn${}_2$
• Pressure dependence of the magnetization in the ferromagnetic superconductor UGe_2
• Non-Fermi Liquid Behavior in U and Ce Alloys: Criticality, Disorder, Dissipation, and Griffiths-McCoy singularities
• Quantum-critical behavior of itinerant ferromagnets
• Observation of two time scales in the ferromagnetic manganite La(1-x)Ca(x)MnO(3), x = 0.3
• Ferromagnetic Quantum Critical Point Avoided by the Appearance of Another Magnetic Phase in LaCrGe${}_3$ under Pressure
• Quantum Tricritical Points in NbFe${}_2$
• Magnetism in Nb(1-y)Fe(2+y) - composition and magnetic field dependence
• Glassy Spin Dynamics in Non-Fermi-Liquid UCu_{5-x}Pd_x, x = 1.0 and 1.5
• Avoided ferromagnetic quantum critical point: Unusual short-range ordered state in CeFePO
• Spectroscopic study of the magnetic ground state of Nb${}_{1-y}$Fe${}_{2+y}$
• Normal and intrinsic anomalous Hall effect in Nb1-yFe2+y
• Susceptibility inhomogeneity and non-Fermi liquid behavior in nominally ordered UCu_4Pd
• Doping driven magnetic instabilities and quantum criticality of NbFe${}_2$
• A Tale of Two Theories: Quantum Griffiths Effects in Metallic Systems
• Ultra-small moment incommensurate spin density wave order masking a ferromagnetic quantum critical point in NbFe${}_2$
• Anomalous quantum-critical spin dynamics in YFe2Al10

Cited by in corpus (1)

• Observation of Mermin-Wagner behavior in LaFeO${}_3$/SrTiO${}_3$ superlattices