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Single crystals of Sr 3 Cr 2 O 8 , Sr 3 Cr 1.9 V 0.1 O 8 and Sr 3 Cr 1.9 Fe 0.1 O 8 were grown using the floating zone technique, and their magnetization behaviors were systematically investigated under pulsed field up to 54 T at various temperatures ranging from 2 K to 20 K. Temperature-induced transition from singlet ground state to triplet state and magnetic-field-induced Bose–Einstein condensation were observed, of which the critical temperature and the critical field are correlative to ion-dopants. The analysis of the ground state and low-field magnetization behaviors indicates that the ion-dopants lead to an enhancement of the intradimer exchange J 0 , which changes the transition temperatures, and increases the critical fields H c1 . The magnetic Fe ion dopant makes the transition from singlet to triplet states more sensitive to the applied magnetic field, in clearly contrast to the situation of the nonmagnetic V 5+ dopant.

In this study we report detailed magnetic property of the 4f-3d pseudo-quaternary Tb0.2Pr0.8(Fe0.4Co0.6)1.88C0.05 compound by detailed magnetization measurements. Very sharp magnetization jumps across the antiferromagnetic–ferromagnetic transition are observed below 3.0 K, and the number of jump-like transitions increases with decreasing temperature. The time-dependent magnetic relaxation, field sweep rate and cooling field dependence of magnetization jumps resemble the martensitic scenario. The number and occurrence of magnetization jumps are mainly determined by the competitions between the thermal fluctuation energy, elastic energy and Zeeman energy, and the field-induced antiferromagnetic to ferromagnetic phase transition at low temperatures is of first-order in nature.

This paper introduces a supercell model to explain the field-induced multiple transitions and the anomalous dilution effect in the nonmagnetic-substituting intermetallic compounds Dy 50− x Al x Ag 50 , in which the shift of the field-induced transitions in the Al-doped samples results from the change of the magnetic structure. At the doping level of x =1.8 (the ratio of Al/Dy approximates 1/26), an anomalous magnetic dilution effect was observed, in which the dilution effect becomes weak and the magnetic behavior is fairly similar to that of pure DyAg. We assumed that the anomalous dilution effect mainly results from the formation of uniform distribution of supercell in the doped Dy 48.2 Al 1.8 Ag 50 .

The enhanced 2D layered structure single crystalline TlCo2Se2 has been successfully fabricated, which exhibits field-induced 3D spin-flop phase transitions. In the case of the magnetic field parallel to the c-axis (B//c), the applied magnetic field induces the evolution of the noncollinear helical magnetic coupling into a ferromagnetic (FM) state with all the magnetization of the Co ion parallel to the c-axis. A striking variation of the field-induced strain within the ab-plane is noticed in the magnetic field region of 20-30 T. In the case of the magnetic field perpendicular to the c-axis (B ⊥ c), the inter-layer helical antiferromagnetic (AFM) coupling may transform to an initial canted AFM coupling, and then part of it transforms to an intermediate metamagnetic phase with the alignment of two-up-one-down Co magnetic moments and finally to an ultimate FM coupling in higher magnetic fields. The robust noncollinear AFM magnetic coupling is completely destroyed above 30 T. In combination with the measurements of magnetization, magnetoresistance and field-induced strain, a complete magnetic phase diagram of the TlCo2Se2 single crystal has been depicted, demonstrating complex magnetic structures even though the crystal geometry itself gives no indication of the magnetic frustration.

Measurements of the isothermal magnetization on La0.27Nd0.4Ca0.33MnO3 have been performed in a field up to 7 T at various temperatures. A distinct field-induced metamagnetic transition is observed within a temperature region of 2–180 K, resulting from the coexistence of charge ordered (CO), antiferromagnetic (AFM) and ferromagnetic (FM) phases. A temperature and magnetic field dependent irreversible CO–FM transition appears in the lower temperature region. Accompanying the transition an obvious lattice strain was observed, indicating that the transition is related to the change of lattice strain due to strong spin–lattice coupling in La0.27Nd0.4Ca0.33MnO3. These properties make the doped manganites a good candidate for a magnetostriction sensor material.

High-quality single-crystal Sr6Co5O15–δ (δ = 1.33) was successfully synthesized with a flux method. Detailed crystalline structure was determined by single-crystal X-ray diffraction at 298 K, which revealed a quasi-one-dimensional Co–O chain-like structure of this oxygen-deficient material. The magnetizations were measured in a pulsed high magnetic field up to 32 T and with a Physical Property Measurement System (PPMS). A large anisotropy and a distinct spin-flip transition were observed in the magnetization behavior. Theoretical calculation based on Botana's results suggests that interchain interaction (non-one-dimensional magnetic coupling) plays an important role in the magnetic properties of Sr6Co5O15–δ.

This research studies the heat transfer characteristic of an unsteady close-contact melting on a flat plate in the cool-thermal discharge systems with external recycle, develops the mathematical model theoretically to simulate the conduction-convection heat-transfer phenomena, and calculates the theoretical prediction of the outlet chilled air temperature by solving the energy balance associated with integral boundary-layer analysis. It is found that the recycle effect can enhance the average Nusselt numbers and heat-transfer efficiency improvement effectively. Three numerical examples of inlet ambient air temperature are illustrated to compute the chilled air temperature, average Nusselt numbers and heat-transfer efficiency with three specified volumetric flow rate and three traversed length of the ambient inlet air as parameters.

Magnetization behavior of (La 0.83 Bi 0.17 ) 0.67 Ca 0.33 MnO 3 has been investigated in the temperature range from 100 to 180 K. A metamagnetic transition was observed in the temperature region, where the magnetization was measured after a zero-field-cooling from room temperature to a selected temperature. Experimental results show that, after a higher magnetization route, the field-increasing branches of the magnetization curves shows an unusual training effect: below a magnetic field H 0 , the applied magnetic field enhances the value of magnetization; however, above H 0 the magnetic field suppresses the value, and the behavior cannot be totally attributed to the enhancement effect of the applied magnetic field on ferromagnetic phase fraction. It is proposed that, in the two-phase coexistence region, the higher magnetic field promotes the phase separation and leads to both the fraction of ferromagnetic domain and the stabilization of antiferromagnetic domain increase.