Exploring quantum Griffiths phase in Ni1−x V x nanoalloys

Abstract

Metallic Ni1−xVx alloys exhibit a ferromagnetic to paramagnetic disordered quantum phase transition in bulk. Such a phase transition is accompanied by a quantum Griffiths phase (QGP), featuring fractional power-law temperature dependences of physical variables, like magnetic susceptibility and specific heat, at low temperatures. As nanoparticles (NP’s) usually exhibit properties significantly different from their bulk counterparts, it is intriguing to explore the occurrence of quantum Griffiths phase in Ni1−xVx nanoalloys. NP’s of Ni1−xVx (0 ≤ x ≤ 0.17) alloys are prepared by a chemical reflux method. The structure and composition of the nanoalloys are determined by X-ray diffraction, X-ray photoelectron spectroscopy and electron microscopy techniques. Metallicity of the samples has been ensured by electrical resistivity measurements. DC magnetization results suggest that ferromagnetism persists in the NP’s until x = 0.17. Low-temperature upturns in magnetic susceptibility and heat capacity hint at critical fluctuations evolving with V-doping. The fluctuations might stem from isolated Ni-clusters within the ferromagnetic NP, indicating a QGP region ranging from x = 0.085 to x ≫ 0.17.

Structural and physical properties of Ni 1−x V x alloys around and away from quantum critical point

“…We observe three peaks and all the peaks were indexed based on fcc structure with space group Fm3m. This is in line with the literature [44]. The absence of any extra features in the diffraction patterns confirms that all the compositions are in single phase.…”

“…Ni 1−x V x undergoes a ferromagnetic quantum phase transition which is strongly influenced by disorder. The magnetic properties of Ni 1−x V x have been studied extensively in the quantum critical region [2,8,[43][44][45]. The results of the magnetic studies show that the quantum phase transition in Ni 1−x V x system is not a clean ferromagnetic to paramagnetic transition.…”

“…The magnetic nature of Ni 1−x V x is well understood but detailed studies of the transport properties are missing in the literature, to the best of our knowledge. With regard to the electrical resistivity and specific heat measurements on Ni 1−x V x alloys, Swain et al [44] have reported the studies around the qcp in nano-alloys of this system. Their results show that the materials are metallic and signature of Griffiths phase have been observed on the basis of the resistivity and heat capacity data analysis, respectively.…”

Engineered protein–iron oxide hybrid biomaterial for MRI-traceable drug encapsulation

“…Small angle electron diffraction (SAED) mode and energy dispersive X-ray spectroscopy (EDS) were employed to confirm that the particles synthesized were, in fact, magnetite-based USPIOs and that they were co-localized with the protein–peptide conjugate by which they were templated. As expected, Q AHA -X-CMms6-templated USPIOs, Q AHA -X-CMms6·USPIO, demonstrated distinct concentric rings typically seen in polycrystalline samples composed of randomly oriented crystallites 71 (Fig. 7).…”

N and V Coincorporated Ni Nanosheets for Enhanced Hydrogen Evolution Reaction

“…The peak at 861.0 eV is the satellite of Ni 2p 3/2 . After the NV coincorporation, the peaks for Ni shift toward higher binding energy, confirming the Ni–V coordination formation . For V 2p (Figure c), the peaks at 514.0 and 521.4 eV are attributed to V 3+ , and the peaks at 516.7 and 524.0 eV are assigned to V 4+ .…”