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Magnetocaloric response in anisotropic single-crystals with cubic crystal symmetry is studied. As compared to isotropic magnets where only paramagnetic-to-ferromagnetic phase transition occurs at Curie temperature ( T C = 185 K) and magnetization increases monotonously with increasing field and/or decreasing temperature, the spin reorientation phase transitions may occur at lower temperatures (∼ 115 K) as the magnetic field gets oriented along one of the cubic anisotropy easy axes and induces nonmonotonic increases in magnetization with increasing field and temperature, leading to a spike-like entropy change (−ΔSM) and positive ΔSM at TC, or move the −ΔSM peak towards higher temperatures. Finally, the power laws of maximum −ΔSM and relative cooling power with the field and the double-shifted loop results evidence that only second-order phase transition occurs and the abnormal magnetization behavior completely comes from the spin order evolution due to energy competition. Therefore, the Maxwell relation is applicable. The results are also suitable for multiple anisotropy or polycrystalline materials with well-defined domains. [ABSTRACT FROM AUTHOR]

SmxPr1-xFeO3 (x = 0, 0.4, 0.7, 0.9, 1.0) all-in-one single crystal rod with quasi-continuous composition distribution was successfully grown by a hetero-seed and hetero-feed optical floating zone technique in flowing air. The lattice mismatch between each adjacent composition is very small, leading to the high-quality continuous growth of SmxPr1-xFeO3 single crystal rod. X-ray back-reflection Laue photographs indicate that all single crystals at different positions along the growth direction have good crystallization quality and the same crystallographic axis. The composition change of the quasi-continuous single crystals along growth direction was analyzed by energy-dispersive X-ray spectroscopy (EDS), which shows that the composition varies continuously and smoothly near the different composition boundaries. At a distance relatively far away from the boundary, the composition remains constant. Finally, we measured the anisotropic magnetic properties of these single crystals when x = 0.7. Our study shows that the hetero-seed and hetero-feed optical floating zone technique has a great potential for high-throughput growth of crystalline materials, and could serve as an effective method to collect single crystal material properties in materials database research. [ABSTRACT FROM AUTHOR]

In the field of plasma diagnosis, the measurement of the distribution function is significant because the distribution function is the basis for the use of plasma kinetic theory and it is the prerequisite for analyzing many physical phenomena, such as Landau damping (wave-particle resonance phenomenon) and ion sheath. Theoretical analysis and a large number of experiments have proved that plasma components do not obey Boltzmann–Gibbs statistics and can be well described by nonextensive statistical mechanics. The field of nonextensive electric probe has also made great progress, and the invention of the nonextensive single electric probes has developed and strengthened the power of plasma diagnostics. The nonextensive electric probe can not only measure the electron nonextensive parameter of plasma that cannot be measured by traditional probes but can also measure more accurate plasma parameters that can also be measured by traditional probes, such as Te, Φp, ne, Φf, and α q F e . However, diagnosing the plasma distribution function by the nonextensive electric probe has not been thoroughly and systematically analyzed and discussed. Here, we show the measurement of the plasma distribution function with a nonextensive single electric probe. This work expands the diagnostic capabilities of the nonextensive single electric probe. We utilize the nonextensive single electric probe theory to analyze the experimental data points of the I–V curve, measure the plasma electron distribution function f v x , and display the distribution curve (figure f-vx), and we also measure the plasma parameters of q F e , Te, Φp, ne, Φf, α q F e , etc. The proposed method provides a new approach to the diagnosis of the plasma distribution function and contributes to a more accurate and comprehensive grasp of plasma, which creates better conditions for us to take advantage of plasma. These initial results illustrate the potential of the nonextensive electric probe in the field of plasma diagnosis and, more generally, in accelerating the progress of fusion-energy science and helping to understand complex physical systems. [ABSTRACT FROM AUTHOR]

The influence of magnetocrystalline anisotropy (K) on the magnetic entropy change (ΔSM) in single crystals under low fields (H) is studied based on unbiased Monte Carlo simulations. When H is applied perpendicular to the easy axis, the positive and negative ΔSM may coexist. The positive ΔSM peak value and its maximum value optimized by the field and the threshold of switching to negative ΔSM depend on K. Moreover, K linearly enhances the blocking temperature where the negative ΔSM maximum is obtained, associated with the decrease in the peak value with increasing K. Finally, the rotating ΔSM under a constant H may be much larger than ΔSM produced by moving the model in and out of the same H, and the best response to K is found at 86° between K and H, independent of the anisotropy magnitude. [ABSTRACT FROM AUTHOR]