In the past few years we have witnessed spectacular development of nano-materials spin crossover complexes 3d4–3d7 transition metal ions, including thin films, nanoparticles, nanopatterns and nanoscale assemblies. These developments were primarily motivated by fundamental questions concerning size reduction effects on bistability properties. On other hand, nano-objects require new characterization techniques (scanning probe microscopy, micro-magnetometry, etc.), revealing unknown details SCO...

Advances in micro- and nanotechnology have led to rapid employment of spintronic sensors both recording non-recording applications. These state-of-the-art magnetoresistive exhibit high sensitivities ultra-low field detectivities that meet requirements smart sensing applications the fields internet things, mobile devices, space technology, aeronautics, magnetic flux leakage, domotics, environment, healthcare. Moreover, their ability be customized miniaturized, ease integration, cost-effective...

Magnetic flux leakage (MFL) detection is frequently used for oil and gas pipeline inspection, especially evaluation of the integrity pipelines. The success MFL technique depends on many parameters. However, a sensitive magnetic sensor an important requirement. Therefore, field sensors based different mechanisms have been developed applied to technique. In this paper, we evidence first time capability innovative device planar Hall magnetoresistance devoted detection. This promising prototype...

Brillouin and Raman scattering experiments have been performed on vitreous silica samples in order to check the validity of several models proposed for interpretation low-frequency part spectrum glasses including so-called ``boson peak.'' Samples various origins, fictive temperatures, impurities contents as well irradiated considered. It is demonstrated that softening acoustic modes responsible variation location boson peak maximum ${\mathrm{\ensuremath{\omega}}}_{\mathrm{max}}$ not fully...

We have investigated the sensitivity of a planar Hall resistance sensor as function ring radius in trilayer structure Ta(3)/IrMn(10)/Cu(0.2)/NiFe(10)/Ta(3) (nm). The diagonal components magnetoresistivity tensor rectangular prism corresponding to anisotropic magnetoresistance are few ten times larger than that off-diagonal component resistance. However, it is noteworthy resultant contribution governed by due cancellation self-balanced bridge configuration. Both experimental and theoretical...

Electronic structures and thermoelectric (TE) properties of KBiBa KBiSr half-Heusler compounds are investigated by using the combined framework first-principles semi-classical Boltzmann transport theory. Elastic phonon calculations reveal that these mechanically dynamically stable. Band calculations, Tran Blaha modified Becke–Johnson potential including spin–orbit coupling, show semiconductors with an indirect bandgap 0.88 0.95 eV respectively. Performing on lattice thermal conductivity,...

In situ postgrowth annealing of (Ga,Mn)As layers under As capping is adequate for achieving high Curie temperatures (TC) in a similar way as ex air or N2 atmosphere practiced earlier. Thus, the first efforts give an increase TC from 68 to 145 K after 2 h at 180 °C. These data, combination with lattice parameter determinations and photoemission results, show that acts efficient sink diffusing Mn interstitials.

The field sensitivity of a planar Hall effect (PHE) micro-ring type biosensor has been investigated as function magnetizing angle the sensor material, for sensing low magnetic moment superparamagnetic labels. is maximal at α = 20°. At this optimized angle, PHE about 3.6 times higher than that measured conventional configuration, 90°. This optimization enables PHE-ring to detect biolabels with ultra-low moments down 4 × 10−13 emu.

Abstract A promising and original method to study the spin‐transition in bistable spin‐crossover (SCO) materials using a magnetoresistive multiring sensor its self‐generated magnetic field is reported. Qualitative quantitative studies are carried out combining theoretical experimental approaches. The results show that only small part of matter dropped on surface probed by device. At low bias‐current range, number detected nanoparticles depends amplitude current. However, agreement with...

The influence of surface/interface on the lattice dynamics spin crossover nanoparticles has been investigated by a spring-ball model solved Monte Carlo methods. bond cohesion energy extracted from M\"ossbauer spectroscopy measurements performed compound ${\mathrm{Ni}}_{3}[\mathrm{Fe}{(\mathrm{CN})}_{6}]$. We show that coupling between bulk and surface vibrational properties, which drastically affects mechanical properties whole particle below characteristic size, major impact phase stability...

We analyse in detail the role of surface relaxations on spin transition phenomenon through an Ising-like model solved inhomogeneous mean field approach. show relaxation tends to decrease energy cost missing bonds. Cooperative phenomena are also affected, leading asymmetric hysteresis loop. The underlying mechanisms investigated by calculating thermodynamics excess quantities. Far from transition, contribution internal energy, entropy and free is negligible, but their becomes substantial...

We report the investigation of size evolution lattice dynamics in spin crossover coordination nanoparticles $\mathrm{[}\mathrm{Fe}(\mathrm{pyrazine})(\mathrm{Ni}{(\mathrm{CN})}_{4})]$ through nuclear inelastic scattering (NIS) measurements. Vibrational properties these bistable molecular materials are paramount importance and NIS permits access to partial vibrational density states both [high (HS) low (LS)] from which thermodynamical mechanical can be extracted. show that reduction leads...

The ability to stabilize the sensitivity of a magnetoresistance sensor in unstable thermal environments is key parameter many high precision measurements. Here, we propose method highly sensitive and low noise magnetic based on planar Hall Effect crossed junction. stability achieved by controlling interplay between Zeeman energy, exchange bias anisotropy energy as function temperature stack comprising trilayer structure NiFe/Cu/IrMn (10/0.12/10 nm). 4.5 ± 0.15 × 10−3 V/A/T/K when external...

Comparative measurements of Brillouin light scattering and ultrasounds in a wide class silica aerogels xerogels show the existence distinct mechanisms governing temperature behaviors acoustic attenuation different frequency ranges. In MHz range is mainly regulated by dynamical due (i) to thermally activated local motions structural defects typical vitreous at low temperatures (ii) relaxations ``extrinsic'' high temperatures, i.e., hydroxyl groups covering inner surface pores aerogels. range,...

Antisymmetric magneto-resistance anomalies generated by a reversal of the magnetization are studied in number GaMnAs/InGaAs layers with out-of-plane (easy axis) magnetization. The occur independent magnetic field orientation. This shows, that once domain reversed is nucleated, simply presence wall between longitudinal contacts sufficient to give rise anomaly. Very different shapes for anomaly can be observed experimentally depending upon sample. They reflect various structures present inside...

Several glass samples taken from one batch and stabilized at different temperatures ${\mathit{T}}_{\mathit{f}}$ in the glass-transition range are studied by Brillouin Raman scattering. We obtain evidence for variations with of profile boson peak (BP). The first sharp diffraction (FSDP) observed on same x-rays shows that two features, BP FSDP, not clearly correlated. results support idea onset is connected high-frequency acoustic phonon damping.

The generalized density of states LaFe4Sb12 and CeFe4Sb12 has been determined by inelastic neutron scattering its main features are found to be in agreement with recently published calculations (J. L. Feldman, D. Singh, C. Kendziora, Mandrus B. Sales, Phys. Rev. B, 2003, 68, 094301). In both compounds a localized vibrational contribution appears superposed on the low-energy Debye response. distinct response La is obtained subtraction data for Ce filled compound it shows even more clearly...

Abstract The temperature dependence of the resistivity, Seebeck coefficient and photoinduced second harmonic generation (PISHG) are studied near quantum critical point in skutterudite compound LaFe 4 Sb 12 , possessing increased spin fluctuations. We observed a large maximum PISHG at about 15 K. signal increases substantially below 35 found correlation between dependences PISHG, resistivity coefficient. proposed phenomenological explanation for occurrence implying strong fluctuations exist...

In the first part of this work, an experimental study lattice dynamics spin crossover nanoparticles was performed using nuclear inelastic scattering (NIS). A size dependence low energy phonon modes appears under 10 nm, but its origin is not well understood. paper, we investigate confinement effects in framework molecular simulations by modeling three-dimensional considering a cubic with octahedral pattern. The vibrational density states computed and compared to experiment. allow one...