12 research outputs found
Magnetic Properties of the Intermetallic Compound with the Cu_3Au-Type Structure in Cobalt-Titanium Alloy System
X-ray and magnetic studies have been made on the intermetallic compound Co_Ti_. X-ray study indicates that Co_Ti_ with the Cu_3Au-type structure has the phase field ranging from about 20.5 to 25.0 at. % Ti (x=0.180~0) below 1,000℃. According to magnetic measurements, Co_3Ti (x=0) is a paramagnetic substance with a practically temperature independent magnetic susceptibility, whereas Co_Ti_ (x>0) is ferromagnetic with Curie points lower than 80°K and saturation magnetizations less than 20.8emu/g
Magnetic Properties of the Stoichiometric Laves Phase Compound in Cobalt-Titanium System
It has been confirmed by X-ray diffraction and magnetic studies that the cubic Laves phase Co_2Ti exists in a composition range of less than one atomic percent around the stoichiometric composition. Magnetic measurements, made in the temperature range from 4.2° to 800°K, indicates that this cubic Laves phase compound is antiferromagnetic with the Neel temperature of 43°K. The reciprocal magnetic susceptibility vs. temperature curve in the paramagnetic state is strongly concave towards the temperature axis. The curve is described by a modified Curie-Weiss law, in which the effective magnetic moment of the cobalt atom is 0.45μ_B
Magnetic Properties of Cobalt-Titanium Alloys with the CsCl-Type Structure
X-ray diffraction and magnetic studies have been made on the intermetallic compound CoTi. X-ray diffraction studies indicate that Co_Ti_with the CsCl-type structure has the single-phase ranging from about 44.5 (x=0.110) to 50.0 at.%Ti(x=0) . According to magnetic measurements, the stoichiometric CoTi appears to be Pauli paramagnetic, whereas in nonstoichiometric cobalt-excess composition an appreciable increase in magnetic susceptibility is observed at low temperatures, which may be attributed to the appearance of magnetic moment in this composition range. The magnetic moment estimated from the observed Curie constant is nearly proportional to x, therefore it may be concluded that the magnetic moment belongs to the excess cobalt atom, which is assumed to be substituted with the titanium atom in the equiatomic composition
Magnetic Properties of the Stoichiometric Laves Phase Compound in Cobalt-Titanium System
It has been confirmed by X-ray diffraction and magnetic studies that the cubic Laves phase Co_2Ti exists in a composition range of less than one atomic percent around the stoichiometric composition. Magnetic measurements, made in the temperature range from 4.2° to 800°K, indicates that this cubic Laves phase compound is antiferromagnetic with the Neel temperature of 43°K. The reciprocal magnetic susceptibility vs. temperature curve in the paramagnetic state is strongly concave towards the temperature axis. The curve is described by a modified Curie-Weiss law, in which the effective magnetic moment of the cobalt atom is 0.45μ_B
Ferromagnetic Properties of the Intermetallic Compound with the Hexagonal Laves-Phase Structure in Cobalt-Titanium System
The homogeneous composition range and magnetic properties of the hexagonal Laves-Phase compound. Co_Ti_ (x<0), have been determined by X-ray diffraction and magnetic studies. X-ray diffraction studies show that the MgNi_2-type structure is stable in a narrow composition range from about 29 to 31.3 at.% Ti at room temperature. Magnetic measurements made at temperatures from 4.2°to 1, 000°K indicate that these MgNi_2 phase compounds are ferromagnetic with Curie points lower than 44°K, showing a conspicuous concave toward the temperature axis in every reciprocal magnetic susceptibility vs. temperature curve above the Curie point. It is shown that magnetic data can be interpreted under the assumption that excess cobalt atoms behave as impurity atoms with a localized moment located in the matrix of a paramagnetic compound, similarly to the case of the analysis of the magnetism of dilute magnetic alloys
Crystal Structures, Homogeneity Ranges and Magnetic Properties of Tantalum-Cobalt Laves Phases(Physics)
The crystal structures, homogeneity ranges and magnetic properties of the three Laves phases in the tantalum-cobalt alloy system have been studied with the aid of the X-ray powder photographs, density and magnetic measurements. The hexagonal MgNi_2-type TaCo_2 compound with the homogeneity range of about 25.5 to 27.0 at.% Ta, is ferromagnetic with Curie temperatures lower than 19 K and saturation magnetizations at 4.2 K less than 3.58 emu/g. The cubic MgCu_2-type one is paramagnetic down to 4.2 K over the whole homogeneity range of about 28.5 to 33.3 at.% Ta. If a relatively strong temperature-dependent magnetic susceptibility of the stoichiometric composition in this compound is analyzed as the band paramagnetism, excess cobalt atoms seem to have very small localized moments in the non-stoichiometric one. Around 40.0 at.% Ta one observed a hexagonal MgZn_2-type which shows Pauli-paramagnetism with the smallest magnetic susceptibility among the three Laves phases
Magnetic Field Effect on Crystalline Nucleation in MgCu_<2-x>Zn_x Alloys(Crystal Growth, Chemical Reaction and Biology)
By the use of an improved vertical Bridgman growth furnace, the magnetic field effect on the formation of crystalline nuclei has been examined for the MgCu_Zn_x alloys with x=0 and 1.15 in a high magnetic field of 100 kOe. It was found that the application of magnetic field during the crystallization tends to suppress the formation of crystalline nuclei for the MgCu_2 alloy ( x=0 ), in contrast to the increase in the number of grains for the MgCu_Zn_ alloy ( x=1.15 ). The experimental results are qualitatively explained by taking into account the contribution from the magnetic free energy change accompanying the formation of a solid from its liquid