Extremely broad hysteresis in the magnetization process of α-Dy2S3 single crystal induced by high field cooling

α-Dy2S3 possesses orthorhombic crystal structure having two crystallograpically inequivalent Dy sites. Magnetization process of α-Dy2S3 single crystal after cooling in the high magnetic field of 18 T has been investigated. The magnetization under the field of 18 T along the α-axis on the cooling process from 150 K shows step-like rises at 70 and 40 K and reaches about 9 μB per one Dy3+ at 1.5 K. This value, which corresponds to 90 % of full saturation moment of Dy3+, is much larger than 6 μB obtained at the same conditions after cooling in no magnetic field (zero-field cooling; ZFC). After cooling to 1.5 K, the magnetization while decreasing field shows abrupt drops at 3.0 and 1.7 T, and then comes to 0 μB at 0 T. Subsequently, while increasing field, the magnetization demonstrates a similar curve to that obtained after ZFC without step-like rise below 13.1 T. At μ0H = 13.1 T, the magnetization rises suddenly and agrees with the curve for the decreasing process. This irreversible magnetization process yields extremely broad hysteresis having width of μ0ΔH = 11.4 T. Broader hysteresis and narrower one are also observed at 4.2 and 10 K, respectively

Effect of a Slope on the Dynamic Properties of Diluvial Terrace

It is well known that landform influences the behavior of the ground during earthquakes. The objective of this study is to clarify the effect of a slope on the dynamic properties of diluvial terrace based on ground investigations, seismic motion observations and twodimensional finite element analyses, by choosing a target area that has a landform typical to the southern Kanto plain in Japan. Through the study, the followings were found: (1) Due to a weak soil along the slope, amplification becomes very large, but the area of influence is relatively small. (2) Amplification due to ground irregularity itself is relatively small, but the area of influence is fairly large. (3) It should be noted that the possibility of slope failure during an earthquake becomes very large at the slope when a weak soil exists along the slope

Novel Magnetic and Thermodynamic Properties of Thiospinel Compound CuCrZrS4_{4}

We have carried out dc magnetic susceptibility, magnetization and specific heat measurements on thiospinel CuCrZrS$_{4}$. Below $T_{\rm C}^{*} =$ 58 K, dc magnetic susceptibility and magnetization data show ferromagnetic behavior with a small spontaneous magnetization 0.27 $\mu_{\rm B}/$f. u.. In dc magnetic susceptibility, large and weak irreversibilities are observed below $T_{\rm f} =$ 6 K and in the range $T_{\rm f}< T < T_{\rm C}^{*}$ respectively. We found that there is no anomaly as a peak or step in the specific heat at $T_{\rm C}^{*}$.Comment: 11 pages, 4 figure

Van Vleck paramagnetism of the thulium garnet Tm3Al5O12

The magnetic susceptibility of the garnet-type single crystal Tm3Al5O12 exhibits the typical Van Vleck temperature independent paramagnetism below ≈8 K. The temperature dependence of the susceptibility over the range 2.0–300 K has been analyzed on the assumption that the cubic crystal-electric-field dominates the energy level on 3H6 (J=6) ground multiplet for Tm3+ ion having 12-electrons in 4f shell. The ground state of the 3H6is nonmagnetic with Γ2 singlet, avoiding the Kramers doublet. The energy separation between Γ2 and the first excited state Γ(2)5 triplet is evaluated to be 68.0 K. The whole energy interval Δ between Γ2 and the highest state Γ1 in 3H6 is estimated to be 339.5 K

Van Vleck paramagnetism of the trivalent Eu ions

Magnetic susceptibilities of Eu2O3, EuF3 and EuBO3 have been measured over the wide temperature range 5 to 650 K. The Van Vleck paramagnetism, with the ground state of 7F0 (S = 3, L = 3), has been investigated comprehensively. The temperature independent paramagnetism emerges manifestly below approximately 100 K. The variation of the susceptibility with temperature for EuBO3 is in satisfactory agreement with the coupling constant λ = 471 K, where the spin-orbit interaction is λL・S for the Russell-Saunders coupling on the basis of Van Vleck theory with one parameter λ. The value of λ = 490 K can fit the susceptibility data of EuF3. The deviation from the theory arises in Eu2O3 . This discrepancy originates mainly from the influence of the crystalline field. Susceptibility of Gd2O3, having the ground state of 8S7/2 (S = 7/2, L = 0), is also presented as a magnetic standard compound in comparison with these results

Evolution from a ferromagnetic to a spin-glass regime in the spinel-type Cu(Cr1-xTix)2S4

Successive changes from ferromagnetic, re-entrant mixed, to spin-glass regime have been manifestly found with increasing Ti-composition x in the quaternary spinel-type Cu(Cr1-xTix)2S4 system. The Curie temperature Tc　decreases steeply with increasing x and this transition becomes ill-defined around x = 0.47. Two distinct transitions appear below Tc over the range x = 0.40 - 0.47. Coexistence of the ferromagnetism and spin-glass order would be observed below the Gabay and Toulouse transition TGT, owing to freezing of the transverse-spin components without changing of the ferromagnetic order parameter. Finally, at a yet lower temperature de Almeida-Thouless transition TAT, the longitudinal-spin component freezes randomly at which an irreversibility arises between zero-field-cooled (ZFC) and field-cooled (FC) magnetizations. Over the range of 0.47 ≤ x ≤ 0.85, a cusp of the ZFC magnetization is seen at Tg like conventional spin-glass. Specimens with x ≥ 0.90 remain paramagnetic down to 2.0 K. A magnetic phase diagram between T versus x has been obtained experimentally. The values of the multi critical point in 100 Oe is detected to be x = 0.47 and T = 7.40 K. The low field magnetization and the phase diagram are satisfactorily explained by the theory of Gabay and Toulouse on the basis of Heisenberg isotropic vector spin model rather than the Ising spin model

Ferromagnetism and the metal-insulator transition in the thiospinel Cu(Ir1-xCrx)2S4

A thiospinel CuIr2S4 exhibits a temperature-induced metal-insulator (M-I) transition at 230 K with a simultaneous spin-dimerization and charge-ordering transition although a three-dimensional system. On the other hand, CuCr2S4 has the same spinel structure without any structural transformations. CuCr2S4 remains metallic and is ferromagnetic with the Curie temperature TC&sime;377 K. In order to see the effect of substituting Cr for Ir on the M-I transition, we have carried out a systematic experimental study of electrical and magnetic properties of Cu(Ir1-xCrx)2S4 system. The M-I transition temperature decreases steeply with increasing Cr-composition x and this transition is not detected above x&sime;0.05. The value of TC decreases with decreasing x from 1.0, then TC disappears below x&sime;0.20. The ferromagnetic state suggests the non-collinear spin alignment. In the intermediate composition range over x=0.08 to 0.20, the B-site undergoes a local crystal distortion around 180 K, where the energy level t2g splits into lower symmetry. Then the low-spin state within the t2g subspace is realized for Cr3+ ion with s=1/2. The magnetic state of Cr3+ ion indicates a crossover from high temperature s=3/2 to low temperature s=1/2 state around 180 K

Spin-glass and novel magnetic behavior in the spinel-type Cu1-xAgxCrSnS4

A dual non-magnetic substitution system on A- and B-sites in the spinel structure has been studied. The mother compound is a ferromagnet CuCr2S4 with the Curie temperature Tc ≅ 380 K. A system of Cu1-xAgxCrSnS4, which is the same notation as (Cu1-xAgx)(Cr0:50Sn0:50)2S4, has been prepared over the entire range of 0.00≦x≦1.00 although the Cr-Sn sublattice is unchanged in the fixed composition of 0.50 on B-sites. All these compounds exhibit the spin-glass phase with the freezing temperature Tg approximately at 16 K in 100 Oe. Since only Cr ions have the magnetic moment on the B-sites, the substitution of Ag for Cu on the A-sites does not influence strongly the spin-glass freezing behavior over the whole composition range. Nevertheless, the magnetization of Cu1-xAgxCrSnS4 with x = 0.50 and 0.55 causes a broad upturn hump over 30–130 K where the spin-glass phase is broken. Strong magnetic field dependence of this hump anomaly has been observed with an irreversibility between zero-field-cooled (ZFC) and field-cooled (FC) magnetizations even though above Tg. The hump is suppressed in higher fields and collapsed down at approximately 1.0 kOe with a tiny trace quantity of the anomaly where the difference between the ZFC and FC processes disappears. The specimen with x = 0.45 shows as mall hump anomaly in low field ≦20 Oe which corresponds to a precursor of the huge anomaly for x = 0.50. The hump anomaly could be attributed to a formation of the cluster-glass. The spin-clusters are embedded in the matrix of spin-glass elements in high degree of disorder without long-range order. All the spins eventually are frozen below Tg. The strange magnetic freezing originates from the delicate dual substitutions. The mechanism of the anomaly is far from a complete picture and remains enigmatic

CHARACTERISTICS IN AN RF SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE AS A FUNCTION OF APPLIED MAGNETIC FLUX : SYSTEMATIC CALCULATIONS Ⅰ

There has been a lot of discussion of characteristics in superconducting quantum interference device (SQUID).However, much less information is available on systematic calculations of these behavior. In this report, we describe various features in a superconducting ring having one Josephson junction. Systematic computer calculations of static behavior of the rf-SQUID have been carried out. The characteristic features depend strongly on a parameter β=(2πLI₀)/Ф₀. where I₀ is a critical current of the junction. L is a self -inductance of the ring and Ф₀ is the flux quantum. In the regime β>1, the quantum states are discrete and the transitions between the quantum states are irreversible. The present work is focused on the correspondence between energy of the system and the characteristics in the rf-SQUID over the range of β= 0.20 to 2π. The results of the calculations are shown in the following No. 2 paper

Spontaneous Cardiac Hypertrophy in a Crl:CD(SD) Rat

Cardiac hypertrophy was observed in a 9-week-old Crl:CD(SD) rat that died unexpectedly. The animal was allocated to the control group of a toxicity study, and no abnormalities in its general conditions, body weight or food intake were observed. Necropsy revealed an increase in heart weight. Gross examination indicated cardiac enlargement with thickening of the right and left ventricular walls. Histopathological examination revealed hypertrophy of the cardiomyocytes in the right and left ventricular walls and the interventricular septum. Electron microscopic examination indicated bizarre nuclei and accumulation of an increased number of various sizes of mitochondria in the perinuclear region of the hypertrophied myocytes. Hypertrophied myocytes connected by intensely folded intercalated disks were also observed. Based on these findings, the animal was diagnosed with cardiac hypertrophy. This is the first case report of cardiac hypertrophy in this strain