Magnetocrystalline Anisotropy and Magnetocaloric Effect Studies on the Room-temperature 2D Ferromagnetic Cr4_4Te5_5

We present a thorough study on the magnetoanisotropic properties and magnetocaloric effect in the layered ferromagnetic Cr$_4$Te$_5$ single crystals by performing the critical behaviour analysis of magnetization isotherms. The critical exponents $\beta$=0.485(3), $\gamma$=1.202(5), and $\delta$=3.52(3) with a Curie temperature of $T_C \approx 340.73(4)$ K are determined by the modified Arrott plots. We observe a large magnetocrystalline anisotropy K$_u$=330 kJ/$m^3$ at 3 K which gradually decreases with increasing temperature. Maximum entropy change -$\Delta S_{M}^{max}$ and the relative cooling power (RCP) are found to be 2.77 $J/kg-K$ and 88.29 $J/kg$, respectively near $T_C$ when the magnetic field applied parallel to $\it{ab}$-plane. Rescaled -$\Delta S_M (T, H)$ data measured at various temperatures and fields collapse into a single universal curve, confirming the second order magnetic transition in this system. Following the renormalization group theory analysis, we find that the spin-coupling is of 3D Heisenberg-type, $\{d:n\}=\{3:3\}$, with long-range exchange interactions decaying as $J (r) = r^{-(d+\sigma)}= r^{-4.71}$.Comment: 10 pages, 7 figure

Parameter identification of BIPT system using chaotic-enhanced fruit fly optimization algorithm

Bidirectional inductive power transfer (BIPT) system facilitates contactless power transfer between two sides and across an air-gap, through weak magnetic coupling. Typically, this system is nonlinear high order system which includes nonlinear switch components and resonant networks, developing of accurate model is a challenging task. In this paper, a novel technique for parameter identification of a BIPT system is presented by using chaotic-enhanced fruit fly optimization algorithm (CFOA). The fruit fly optimization algorithm (FOA) is a new meta-heuristic technique based on the swarm behavior of the fruit fly. This paper proposes a novel CFOA, which employs chaotic sequence to enhance the global optimization capacity of original FOA. The parameter identification of the BIPT system is formalized as a multi-dimensional optimization problem, and an objective function is established minimizing the errors between the estimated and measured values. All the 11 parameters of this system (Lpi, LT, Lsi, Lso, CT, Cs, M, Rpi, RT, Rsi and Rso) can be identified simultaneously using measured input–output data. Simulations show that the proposed parameter identification technique is robust to measurements noise and variation of operation condition and thus it is suitable for practical application

Effect on the Electronic and Magnetic Properties of Antiferromagnetic Topological Insulator MnBi2_2Te4_4 with Sn Doping

We thoroughly investigate the effect of nonmagnetic Sn doping on the electronic and magnetic properties of antiferromagnetic topological insulator MnBi$_2$Te$_4$. We observe that Sn doping reduces the out-of-plane antiferromagnetic (AFM) interactions in MnBi$_2$Te$_4$ up to 68\% of Sn concentration and above the system is found to be paramagnetic. In this way, the anomalous Hall effect observed at a very high field of 7.8 T in MnBi$_2$Te$_4$ is reduced to 2 T with 68\% of Sn doping. Electrical transport measurements suggest that all compositions are metallic in nature, while the low-temperature resistivity is sensitive to the AFM ordering and to the doping-induced disorder. Hall effect study demonstrates that Sn actually dopes electrons into the system, thus, enhancing the electron carrier density almost by two orders at 68\% of Sn. In contrast, SnBi$_2$Te$_4$ is found to be a p-type system. Angle-resolved photoemission spectroscopy (ARPES) studies show that the topological properties are intact at least up to 55\% of Sn as the Dirac surface states are present in the valance band, but in SnBi$_2$Te$_4$ we are unable to detect the topological states due to heavy hole doping. Overall, Sn doping significantly affects the electronic and magnetic properties of MnBi$_2$Te$_4$.Comment: 8 pages and 6 figure

TRADITIONAL AND ONLINE CONSUMERS IN CHINA: A PRELIMINARY STUDY OF THEIR PERSONALITY TRAITS AND DECISION-MAKING STYLES

Background: Population of online consumers increases rapidly, but the decision-making styles of online consumers and psychiatric denominators such as the personality correlates remain unclear. Subjects and methods: In 196 traditional, and 196 age-, education- and gender-matched online consumers, we have tested the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ) and the Consumer Style Inventory (CSI). Results: After exploratory and confirmatory factor analyses, we have defined a five-factor model CSI with 24 items. Online consumers scored lower on ZKPQ Neuroticism-Anxiety and higher on Aggression-Hostility than traditional ones did, and scored higher on CSI Novelty-fashion consciousness and Brand consciousness, and lower on Time consciousness than the traditional consumers did. ZKPQ Neuroticism-Anxiety was positively correlated with CSI Confused by overchoice in both groups, Sociability was positively correlated with Novelty-fashion consciousness and negatively with Time consciousness in traditional group, and Impulsive Sensation Seeking was positively correlated with Novelty-fashion consciousness and Time consciousness in online group. Conclusions: Our study suggests that, regarding the decision-making styles, online consumers display curiosity that lacks security and need other ways to improve their social lives. It also calls further designs to address the contributions of other psychiatric features to the particular decision-making styles in online consumers

Diffusive motion in aqueous solutions

857-861The interest in diffusion phenomena arises from both applied and fundamental points of view and in recent years, there has been some spectacular development in this study both theoretically and experimentally. Inelastic neutron scattering, NMR, optical and above all radioactive tracer techniques have accumulated important information about the migration of ions, or molecules through a maze of molecules. The difficulty in the study of liquids lies in the fact that, kinetic energy and potential energy of the constituent particles in a liquid are comparable and both must be taken into account to calculate any property, which is to be compared with observed results. In general, by employing techniques which increase the thermal motion of the constituent particles or by varying the composition of the binary and ternary systems, much information can be gathered about liquids and, in this respect, diffusion study in liquids is an important tool. It is very interesting and very important to observe the change in diffusion coefficient in some aqueous solution with the introduction of known amounts of some other salts or acids. This study of coupled flow has been undertaken by several groups of workers. A sliding cell method based on radioactive tracer technique has been developed in the laboratory of the author and it has been used to measure diffusion coefficient in H3PO4-H2O system containing different amount of salts of this weak acid. Different radioactive isotopes like Na-22, Na-24, Hg-203, Ga-72, Cs-134, Cs-137, TI-204, P-32 etc., have been used in the laboratory for diffusion measurements in different systems. Irreversible thermodynamical principles have been applied to explain the observed results. Both H2O and D2O have been employed as solvents and the breaking of their structures with the introduction of salts have been explained.</span