Analysis Of Critical Behavior Research Articles

Magnetocaloric effect, magnetotransport and magnetic properties of polycrystalline Pr(0.65-x)GdxSr0.35MnO3 (x ≤ 0.3) compounds

Polycrystalline Pr0.65-xGdxSr0.35MnO3 (x = 0.01, 0.05, 0.1, 0.2, 0.3) manganites were prepared by conventional solid-state method. Structural analysis has revealed a change in structure with x = 0.2, from Rhombohedral (R-3c) to Orthorhombic (Pbnm) symmetry. Small oxygen deficiency was found in the samples. The electrical measurements revealed typical colossal magnetoresistance (CMR) behavior, with single metal–insulator peak at Tp for all investigated samples. The small polaron hopping (SPH) and variable-range hopping (VRH) models were used to describe the electrical conduction above Tp. Magnetic measurements show an increase in magnetization below the Curie temperature, TC. Values of Tc diminish with increasing Gd3+ content. Isothermal measurements around critical points suggest a possible interaction between the 4f-ions and Mn-sublattice The magnetic critical behavior analysis established the tri-critical mean-field model to be the governing model for the series. Large magnetic entropy change ΔSM at near room temperature (278 K) was exhibited by the x = 0.01 sample at 2.2 J/kgK in μ0ΔH = 1 T and 5.36 J/kgK in μ0ΔH = 4 T. The largest |ΔSM| value was shown by the x = 0.1 sample. The values of the relative cooling power (RCP) and the temperature-averaged entropy change (TEC) increased with substitution qualifying these compounds as magnetocaloric materials.

Anisotropic magnetic entropy change and magnetic critical behavior in van der Waals Fe3GaTe2

Fe3GaTe2, with intrinsic magnetism at ambient temperature and high perpendicular magnetic anisotropy, is a promising van der Waals material for 2D-materials-based spintronic devices. Herein, we report the anisotropic magnetocaloric effects and magnetic critical phenomena in Fe3GaTe2 single crystal. Owing to the large anisotropy, magnetic entropy change (−ΔSM) shows anisotropic character with −ΔSMmax of 1.67 J kg−1 K−1 along the c axis and 1.11 J kg−1 K−1 in the ab plane under field change of 5 T. The rotating ΔSM from the ab plane to the c axis reaches 0.67 J kg−1 K−1 at magnetic field of 5 T. By carefully fitting the −ΔSMmax and relative cooling power (RCP), we determine their relationships to be −ΔSMmax∝Hn (n = 0.694(1)) and RCP∝Hm (m = 1.301(3)) for the magnetic field along the c-axis. Further analysis of critical behavior near TC reveals critical exponents β = 0.41(1) at TC = 341.5(1) K, γ = 1.01(1) at TC = 341.6(3) K, and δ = 3.67(15) at TC = 340 K, indicating a three-dimensional complex magnetic exchange.

Tuning the magnetocaloric and structural properties of La0.67Sr0.28Pr0.05Mn1–xCoxO3 refrigeration materials

Abstract The structural, magnetic and magnetocaloric properties of perovskite manganites La0.67Sr0.28Pr0.05Mn1−x Co x O3 (x = 0.05, 0.075 and 0.10) (LSPMCO) are investigated. LSPMCO crystallizes as a rhombohedral structure with R-3c space group. As the Co content increases, the cell volume expands, the Mn–O–Mn bond angle reduces and the length of the Mn–O bond increases. The samples show irregular submicron particles under a Zeiss scanning electron microscopy. The particle size becomes larger with increasing doping. The chemical composition of the samples is confirmed by x-ray photoelectron spectroscopy (XPS). The ferromagnetic (FM) to paramagnetic (PM) phase transition occurs near the Curie temperature (T C), and all transitions are second-order phase transitions (SMOPT) characterized by minimal thermal and magnetic hystereses. Critical behavior analysis indicates that the critical parameters of LSPMCO closely align with those predicted by the mean-field model. The T C declines with Co doping and reaches near room temperature (302 K) at x = 0.075. The maximum magnetic entropy change ( − Δ S M max ) at x = 0.05 is 4.27 J/kg⋅K, and the relative cooling power (RCP) peaks at 310.81 J/K. Therefore, the system holds significant potential for development as a magnetic refrigeration material, meriting further professional and objective evaluation.

Near-room-temperature magnetic properties and magnetocaloric effect of polycrystalline and nano-scale manganites Pr(0.65-x)NdxSr0.35MnO3 (x ≤ 0.35)

Here we report investigations of structural, electrical and magnetic properties of bulk and nano-sized Pr0.65-xNdxSr0.35MnO3 compounds (x ≤ 0.35). Polycrystalline compounds were produced by solid – state reaction and nanocrystalline samples were obtained by sol–gel method. Analysis of x-ray diffraction patterns revealed a change in lattice structure from ‘Pbnm’ to ‘R3c’ symmetry, with diminishing cell volume upon increasing Nd ions substitution for all samples. Optical microscopy was used for bulk surface morphology and transmission electron microscopy was implemented for nano-sized samples. Iodometric titration showed oxygen deficiency for bulk compounds and oxygen excess for nano-sized particles. Measurements of resistivity of bulk samples revealed a single peak at temperatures associated with grain boundary conditions and with ferromagnetic/paramagnetic transition and negative magnetoresistivity. Critical magnetic behavior analysis disclosed that the polycrystalline samples are governed by a tricritical mean field and by 3D Heisenberg models while nanocrystalline samples are governed by a mean field model. Curie temperature Tc values remain in near room temperature range for all bulk compounds; they lower with increasing Nd ions substitution from 295 K for the parent bulk compound to 268 K for x = 0.35. Tc is lowered from 255 K for the parent nano-sized compound in small temperature intervals. All compounds exhibit second-order magnetic phase transitions and relatively high magnetic entropy change, with the highest value of 5.74 J/kgK for x = 0.25 bulk sample in μ˳∆H = 4 T. Strong magnetocaloric effect, stability and the possibility of fine-tuning Tc by Nd ions substitution make the investigated bulk polycrystalline compounds promising for application in magnetic refrigeration. Nano-sized samples possess lower magnetic entropy changes of maximum 2.4 J/kgK in μ˳∆H = 4 T for x = 0.15, but wider effective entropy change temperature (δTfwhm) and relative cooling power on par with other manganites, bringing them into the conversation as a viable option in cooling materials.

Role of Griffiths phase on magnetocaloric properties and critical behavior of half-doped manganites [La0.5Sr0.5-xCaxMnO3(x = 0, 0.25, 0.5)

In this article, a comprehensive study of the effect of calcium substitution on structural magnetic, magnetocaloric properties, and role of Griffiths phase on magnetocaloric properties of half-doped manganites La0.5Sr0.5-xCaxMnO3(x=0,0.25,0.5)] have been presented. A structural phase transition I4/mcm - Pbnm is observed in the whole series. The system exhibits two magnetic transitions for Ca-00 and Ca-25, whereas only one phase transition is observed for Ca-50. Paramagnetic (PM)-ferromagnetic (FM) transition is observed in the whole series and ferromagnetic (FM) - antiferromagnetic (AFM) phase transition is only observed in Ca-25. Interestingly, short range FM clusters exist in the PM matrix of Ca-50, which is a signature of Griffiths phase (GP). The confirmation of GP has been carried out by performing iso-field magnetization measurements at 200 Oe, 500 Oe, and 1 kOe, respectively. Further magnetocaloric properties have been discussed on the basis of isothermal magnetization curves recorded at certain temperature intervals. Calcium substitution favors the enhancement of magnetic entropy change in the series, especially for Ca-50, a magnetic entropy change of 4.5J/(kgK) with relative cooling power of 180J/kg under 5T magnetic field was observed. Iso-field magnetization and magnetocaloric effect along with critical behavior analysis have been carried out to probe the GP and other inhomogeneities present in the respective series.

Complex magnetic interactions and critical behavior analysis in quaternary CoFeV0.8Mn0.2Si Heusler alloy

We investigate the magnetic behavior and critical exponents of quaternary CoFeV0.8Mn0.2Si Heusler alloy to understand the interactions across the Curie temperature (TC). The Rietveld refinement of the x-ray diffraction pattern with the space group F4¯3m confirms a single-phase cubic Y-type crystal structure. The magnetic susceptibility χ(T) data show a ferromagnetic nature with a second-order phase transition from paramagnetic to ferromagnetic at 446±1 K. The saturation magnetization at 5 K is found to be 2.2 μB/f.u., which is close to the Slater–Pauling rule and indicates its half-metallic nature. The values of asymptotic critical exponents (β, γ, and δ) and the TC are extracted through detailed analytical analysis including the modified Arrott plot, the Kouvel–Fisher (K–F) method, and the Widom scaling relation. Interestingly, the estimated values of β=0.369 and γ=1.445 closely approximate the theoretical values of the 3D Heisenberg model across the TC and validate the second-order thermodynamic phase transition. The obtained exponents lead to the collapse of renormalized isotherms, represented by the relationship between the magnetization (m) and the applied magnetic field (h), into two distinct branches above and below the TC, which validates the reliability of the analysis. Furthermore, these exponents suggest that the spin interaction follows a decay pattern of J(r)∼r−4.99, indicating a short-range magnetic ordering, akin to the itinerant-electron 3D Heisenberg model.

Critical behavior and its correlation with magnetocaloric effect in amorphous Fe68+xCr12-xSi8B12 (x=0, 4 and 10) ribbons

Using the melt-spinning technique, ribbons made of amorphous Fe68+xCr12-xSi8B12 with varying compositions of x (0, 4, and 10) were fabricated. The transition temperature can be tuned from 360 (for x = 0) to 610 K (for x = 10) with decreasing Cr content. Around the Curie temperature, there is a magnetic transition known as second-order paramagnetic to ferromagnetic (PM-FM) magnetic transition (SOMT) that the ribbons experience. Our exploration of magnetic interaction involves analyzing critical behavior through various methods including the modified Arrott plot (MAP), Kouvel-Fisher method (K–F), and critical isotherm analysis (CIA). Upon determining critical exponents values (β, γ, and δ), we found them to be in proximity to those anticipated for the short-range 3D-Heisenberg model. Furthermore, an independent analysis of critical behavior was performed using the magnetocaloric effect (MCE) to confirm these findings.

Anomalous critical behavior and localized ferromagnetism of the half‐metallic double perovskite Sr2CrReO6

AbstractDouble perovskites such as Sr2CrReO6 attract great scientific attention owing to their high Curie temperatures (TC ≥ 550 K) as well as large magnetoresistances. However, both the specific physical mechanism of high TC and magnetic ground state in Sr2CrReO6 remain ill‐defined. In order to clarify and understand these issues, we studied its critical phase transition characteristics using critical behavior analysis. We found that the obtained critical exponents (β = 1.115 and γ = 2.224) are quite different from any traditional universality class. The abnormal critical behavior implies that at the quantum critical point, Sr2CrReO6 exists a strong competition among several magnetic interactions. By analyzing their effective critical exponents, we show that the double perovskite Sr2CrReO6 is really an ordered and homogeneous ferromagnet. With the help of Takahashi's theory, the nature of ferromagnetism in Sr2CrReO6 is confirmed to be localized instead of itinerant. The results of this research will provide new insights into the origins of high TC as well as the magnetic ground state in this double perovskite.

Structural, magnetocaloric effect, critical behavior, and spin resonance analysis of monovalent-doped manganites Nd0.6Sr0.4−xMxMnO3 (x = 0.0, 0.1; M = K, Na)

Structural, magnetocaloric effect, critical behavior, and spin resonance analysis of monovalent-doped manganites Nd0.6Sr0.4−xMxMnO3 (x = 0.0, 0.1; M = K, Na)

Investigating the structure, magnetism, magnetocaloric effects and critical behavior of Eu(Ti,B)O3 perovskites

EuTiO3 exhibits various interesting physical properties, including magnetocaloric effect, quantum paraelectricity, magnetoelectricity, and multiferroic properties, thus attracting a broad range of attention from the researchers. The delicate balance between ferromagnetic coupling and antiferromagnetic interactions offers the feasibility of modulating the magnetic properties and magnetocaloric effect for this perovskite. Herein, a range of Eu(Ti,B)O3 perovskites were prepared by substituting titanium with different amounts of boron. A comprehensive investigation on their structure, magnetism, magnetocaloric effect, and critical behavior was performed. All the compounds are confirmed to be crystallized in a single cubic perovskite structure with space symmetry of Pm3m, with the introduced boron uniformly distributed in the compounds. The transition temperatures are determined to be 6.0, 6.5, 5.0, and 5.0 K for EuTi0.9375B0.0625O3, EuTi0.875B0.125O3, EuTi0.8125B0.1875O3, and EuTi0.75B0.25O3, respectively. The results of both magnetic measurements and critical behavior analysis suggest that appropriate substitution of boron promotes the magnetic transition from AFM to FM in Eu(Ti,B)O3. In addition, significantly enhanced low-field magnetocaloric effects were observed in these perovskites. Under field changes of 0–1 and 0–2 T, the values of -ΔSMmax are 14.7 and 26.4 J·kg−1·K−1 for EuTi0.8125B0.1875O3, 15.2 and 27.4 J·kg−1·K−1 for EuTi0.75B0.25O3, respectively.

Analysis of critical current and hot spot behavior in Bi-2223 stacked-tape cable for fusion reactor

The cable-in-conduit-conductor (CICC) based on Bi2Sr2Ca2Cu3Ox (Bi-2223) tape has potential to be used in fusion magnets duo to its high current-carrying capacity under high field and low temperature. In this study, the optimized study on the stacked tape cable based on Bi-2223 tape was performed. The effect of the quantity of grooves and tapes on the critical current is studied by the finite element method, respectively. The comparison between the copper and aluminum frame on the quench behavior of cable is also discussed. The results shows that the critical current of cable is mainly determined by the quantity of tape in cable where the self-field effect has little impact on the critical current in 4.2 K and 15 T. The minimum quench energy (MQE) is proportional to the tape numbers where the MQE with copper frame is higher than that with aluminum frame. The hot spot temperature is decreased with tape numbers for cable with aluminum frame, however, the effect of tape numbers on the hot spot temperature of cable with copper frame is not obvious where the quench is triggered by MQE. Moreover, the cable with lower quantity of grooves shows higher stability compared with other variants containing the same number of tapes.

Magnetic Properties and Magnetocaloric Effect of Polycrystalline and Nano-Manganites Pr0.65Sr(0.35-x)CaxMnO3 (x ≤ 0.3).

Here we report investigations of bulk and nano-sized Pr0.65Sr(0.35-x)CaxMnO3 compounds (x ≤ 0.3). Solid-state reaction was implemented for polycrystalline compounds and a modified sol-gel method was used for nanocrystalline compounds. X-ray diffraction disclosed diminishing cell volume with increasing Ca substitution in Pbnm space group for all samples. Optical microscopy was used for bulk surface morphology and transmission electron microscopy was utilized for nano-sized samples. Iodometric titration showed oxygen deficiency for bulk compounds and oxygen excess for nano-sized particles. Measurements of resistivity of bulk samples revealed features at temperatures associated with grain boundary condition and with ferromagnetic (FM)/paramagnetic (PM) transition. All samples exhibited negative magnetoresistivity. Magnetic critical behavior analysis suggested the polycrystalline samples are governed by a tricritical mean field model while nanocrystalline samples are governed by a mean field model. Curie temperatures values lower with increasing Ca substitution from 295 K for the parent compound to 201 K for x = 0.2. Bulk compounds exhibit high entropy change, with the highest value of 9.21 J/kgK for x = 0.2. Magnetocaloric effect and the possibility of tuning the Curie temperature by Ca substitution of Sr make the investigated bulk polycrystalline compounds promising for application in magnetic refrigeration. Nano-sized samples possess wider effective entropy change temperature (ΔTfwhm) and lower entropy changes of around 4 J/kgK which, however, puts in doubt their straightforward potential for applications as magnetocaloric materials.

Fe-doping modulated critical behavior and magnetocaloric effect of magnetic Weyl Co3Sn2S2

${\mathrm{Co}}_{2.5}{\mathrm{Fe}}_{0.5}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$ single crystal was grown by a flux method, and its magnetocaloric effect and critical behavior were systematically investigated. Significant changes in magnetic properties and critical behavior were observed in Fe-doped ${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$, compared with undoped ${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$. Specifically, the magnetization of ${\mathrm{Co}}_{2.5}{\mathrm{Fe}}_{0.5}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$ measured at a low magnetic field ($H<500$ Oe, $H\ensuremath{\parallel}c$ axis) does not show the thermal hysteresis phenomenon, whereas it was observed in ${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$ near ${T}_{\mathrm{c}}$, which is characteristic of a typical second-order phase transition. Previous reports usually attribute the suppression of ferromagnetism by the substitution of Fe for Co to the decrease in the number of $3d$ electrons. Herein, according to the first-principles calculation, the magnetic moments of dopant Fe align antiparallelly to those of Co atoms, which is also the possible reason for the decrease in magnetization. The critical behavior analysis shows that the critical exponents of the Fe-doped sample around magnetic transition are very close to theoretical values of the mean-field model. Furthermore, the exchange interaction distance $J(r)\ensuremath{\approx}{r}^{\ensuremath{-}4.65}$ and the Rhodes-Wolfarth ratio (RWR) (RWR > 1) prove the long-range itinerant ferromagnetism. The hybridization between the $3d$ orbitals of Fe/Co and the orbitals of $\mathrm{Sn}\text{\ensuremath{-}}5p/\mathrm{S}\text{\ensuremath{-}}3p$ may be an important factor for long-range itinerant ferromagnetism. The zero-field cooling magnetization ($H=100$ Oe, $H\ensuremath{\parallel}\phantom{\rule{0.16em}{0ex}}ab$ plane) undergoes the spin reorientation around 76 K, maybe because the magnetic moments of Fe, aligning antiparallelly to moments of Co atoms, reorient from out of plane to in plane. The critical behavior analysis shows that the first-order phase transition may occur below ${T}_{\mathrm{c}}$ in the case of the $H\ensuremath{\parallel}\phantom{\rule{0.16em}{0ex}}ab$ plane.

The Near-Critical Two-Point Function and the Torus Plateau for Weakly Self-avoiding Walk in High Dimensions

We use the lace expansion to study the long-distance decay of the two-point function of weakly self-avoiding walk on the integer lattice $$\mathbb {Z}^d$$ in dimensions $$d>4$$ , in the vicinity of the critical point, and prove an upper bound $$|x|^{-(d-2)}\exp [-c|x|/\xi ]$$ , where the correlation length $$\xi $$ has a square root divergence at the critical point. As an application, we prove that the two-point function for weakly self-avoiding walk on a discrete torus in dimensions $$d{>}4$$ has a “plateau.” We also discuss the significance and consequences of the plateau for the analysis of critical behaviour on the torus.

Selecting optimal R6TX2 intermetallics (R = Gd, Tb, Dy; T = Mn, Fe, Co, Ni; X = Sb, Te) for magnetic refrigeration.

A complete experimental study of the physical properties playing a relevant role in the magnetic refrigeration application (structural, magnetic, magnetocaloric and thermal) has been performed over nine selected Fe2P-type R6TX2 (R = Gd, Tb, Dy; T = Mn, Fe, Co, Ni; X = Sb, Te) intermetallic compounds, to work close to room temperature. Two magnetic phase transitions are observed for these materials: a paramagnetic to ferromagnetic transition in the range of 182-282 K and a spin reorientation transition in the range of 26-76 K. As a consequence, two peaks related to a direct magnetocaloric effect (DMCE) appear with the magnetic entropy change, generating a wide table-like plateau region in between both peaks, which is required to improve the efficiency of refrigerators following an Ericsson cycle. The highest magnetic entropy peak value for μ0ΔH = 5 T is found for Tb2Dy4FeSb2, with 7.72 J kg-1 K-1 around 182 K. For the same applied field the other compounds show moderate values around room temperature (2.88-4.53 J kg-1 K-1). However, the superposition of the two peaks results in huge refrigerant capacity values, up to RCFWHM(5 T) = 1103.04 J kg-1 in the case of Tb2Dy4FeSb2. The thermal diffusivity, thermal effusivity, thermal conductivity and specific heat capacity have been measured at room temperature, and the temperature dependence of the former has been obtained around the relevant magnetic phase transition region, with values in the range of 1.3-2.3 mm2 s-1, which are good for magnetic refrigerators at high working frequencies. The study is completed with a rigorous critical behavior analysis of the second order PM-FM transition. The critical exponent γ points to long range order interactions, in general, while β values are in the range of 0.59-0.90, indicating a deviation from theoretical models as a reflection of the magnetic complexity in these compounds. The critical exponents have been used to confirm the scaling relations of magnetocaloric properties, and the scaling of refrigerant capacity (RC) values in materials exhibiting two magnetic phase transitions is addressed, concluding that for a correct scaling of RC the magnetic entropy change peak must be considered symmetric. The role of each atom in the properties of the compounds is discussed.

Multiple metamagnetic transitions induced by high magnetic field in DyBi

The rare-earth monopnictide compounds have recently received considerable attention in condensed matter physics because of their correlation between magnetism, crystallographic structure, and transport. Here, we report experimental observations of high-magnetic-field-induced multiple metamagnetic transitions and magnetic structures in DyBi single crystals. The external field up to 32 T is applied in three distinct crystallographic directions as $H//[001]$, $H//[011]$, and $H//[111]$, which reveals anisotropic magnetism as well as multiple metamagnetic transitions. Two field-induced magnetic phase transitions at 3.7 T and 4.9 T along $H//[001]$, two at 3.8 T and 24 T along $H//[011]$, and one at 3.8 T along $H//[111]$ are identified. In order to unveil the nature of magnetic interaction in DyBi, the critical behavior analysis for $H//$[001], a direction with typical magnetism and transitions, is performed. The yielded critical exponents $\ensuremath{\beta}=0.234(8)$, $\ensuremath{\gamma}=0.904(3)$, and $\ensuremath{\delta}=5.03(2)$ agree well with the theoretical prediction of a tricritical mean-field model, indicating a field-induced tricritical phenomenon in this system. Comprehensive magnetic phase diagrams for $H//[001]$, $H//[011]$, and $H//[111]$ are constructed based on detailed magnetization measurement and scaling, which reveal multiple phases such as NiO-type antiferromagnetic (AFM), HoP-type AFM, forced ferromagnetic (FFM), and paramagnetic (PM) phases. Two tricritical points (TCPs) are determined at the intersections of the AFM, FFM, and PM phases, with TCP = (8.6 K, 85 kOe) for $H//$[001] and (16.8 K, 243 kOe) for $H//$[011]. The recognition of multiple phases suggests delicate and complex competition and balance between variable couplings in this system.

The magnetic, thermal transport properties, magnetothermal effect and critical behavior of Co3Sn2S2 single crystal

AbstractThrough the magnetic/thermal transport measurements combined with the analyses of magnetocaloric effect and critical behavior of Co3Sn2S2 single crystal, the main results we obtained are as follows: in the case of the magnetic field H//c‐axis, Co3Sn2S2 exhibits the phase‐separation state below Tc in the low‐field region (H < 500 Oe). Tc increases slightly from 174 to 177 K with an increase in H from 100 to 10 kOe. The second‐order magnetic phase transition near Tc and the itinerant ferromagnetism below Tc are identified. The magnetization below Tc matches well with the three‐dimensional Ising model, instead of the mean‐field model. In the case of H//ab, Tc changes between 175 and 178 K with varying H. Noticeably, M above Tc exhibits a small positive value, instead of the null M as commonly expected in the paramagnetic region. An extra phase transition below 166 K is observed. The magnetic transition near Tc seems not to be the second‐order phase transition. All results show a significant characteristic of anisotropic magnetic phase transition for the Co3Sn2S2 single crystal. They support mutually those in previous reports, moreover, some new phenomena are also observed. They also provide the experimental evidences for the deep insight into the magnetic phase–transition behavior of Co3Sn2S2.

Comprehensive driver behaviour review: Taxonomy, issues and challenges, motivations and research direction towards achieving a smart transportation environment

The aim of this article is to review and analyse previous academic articles associated with car behaviour analysis for the period of 2010 to June 10, 2021 and understand the benefits of using data collection devices. Articles related to car driver behaviour and sensor utilisation are systematically searched. Three major databases – ScienceDirect, IEEE Xplore and Web of Science – were searched. A set of inclusion and exclusion criteria were developed for the search protocol. All articles were coherently classified via taxonomy. Also. The motives that have led researchers to continue their investigations are explored. The challenges and issues of driver behaviour analysis are illustrated with respect to power consumption, data analysis, detection, cost, security and privacy, sensor usage and individual challenges. The research direction of this review points towards different aspects based on the critical analysis of the different scenarios of driver behaviour studies in real time situations. Here, the critical behaviour analysis of intelligent transportation system development is addressed. The gaps in the reviewed articles include the following: sensors used during experiments, the effect of thresholds on labelling processes or data balancing and classification accuracy, the thresholds in identifying driving styles in the car-following model, insufficient experiment size (large scale or small scale) and limitations in data pre-processing. An implementation map depicting the steps of the case study is provided to give insights into the procedures and the problems they address. This review is expected to offer valid and clear points, contributing to the enhancement of driver behaviour research.

Synthesis and critical behaviour analysis of multicomponent Ni0.43Zn0.28Fe0.57Cu0.31Mn1.41O4 spinel oxide

This paper presents synthesis and analysis of critical behavior of (Ni,Zn,Fe,Cu,Mn)3O4 spinel-oxide ceramics near magnetic phase transition. In order to investigate the critical point, a modification of the standard analysis of Arrott-Noakes diagrams was proposed. This new approach takes into account the quality of straightness of isotherms and the fact that the critical straight line (at T=Tc) must pass through the origin of the coordinate system. The determined values of critical parameters β= 0.446, γ= 1.179, and δ= 3.637 are close to those of the mean-field model (β= 0.5, γ= 1, and δ= 3) signifying mainly the isotropic, long-range exchange interactions in the studied ceramic oxide. The self-consistency of the obtained results was confirmed taking into account the scaling theory, and the asymptotic relations for the behaviour of magnetization M in the limits as T→Tc and H→0.

Structure, Magnetocaloric Effect and Critical Behavior of the Fe60Co12Gd4Mo3B21 Amorphous Ribbons.

The aim of the paper was to study the structure, magnetic properties and critical behavior of the Fe60Co12Gd4Mo3B21 alloy. The X-ray diffractometry and the Mössbauer spectroscopy studies confirmed amorphous structure. The analysis of temperature evolution of the exponent n (ΔSM = C·(Bmax)n) and the Arrott plots showed the second order phase transition in investigated material. The analysis of critical behavior was carried out in order to reveal the critical exponents and precise TC value. The ascertained critical exponents were used to determine the theoretical value of the exponent n, which corresponded well with experimental results.