Composition, Temperature, and Ordering Dependence of Magnetostriction Constants in Nickel-Manganese Alloys

Magnetostriction constants, λ_ and λ_&lt111>, in the state quenched from 700℃ of nickel and 3.1, 7.0, 14.2, 18.7 and 25.1 at.% Mn-Ni alloys and those in well-annealed state of 25.1 at.% Mn-Ni alloy have been determined in the temperature range between room and liquid air temperatures. In the quenched state, both constants decrease in magnitude roughly monotonically with increasing Mn content in this temperature range. It seems, however, that each of the magnetostriction constants vs. composition curves at temperatures near liquid air temperature has an inflection point at about 5 at.% Mn. The temperature dependence of the magnetostriction constants in the quenched state is roughly the same irrespective of the composition. A well-annealed Ni_3Mn alloy has fairly large negative magnetostriction constants, which decrease in magnitude rather rapidly with rising temperature, suggesting the occurrence of the change in their signs well below the Curie temperature. The composition dependence of the magnetostriction constants in disordered Ni-Mn alloys and the magnitude of the magnetostriction constants of an ordered Ni_3Mn alloy are discussed in terms of atom pair interactions, of which the magnitudes are assumed to depend on the atomic magnetic moments

Magnetostriction Constants of Face-Centered Cubic Nickel-Copper and Nickel-Cobalt Alloys

The magnetostriction constants, λ_ and λ_ of face-centered cubic Ni-Cu and Ni-Co alloys have been determined at room temperature, using single-crystal disc specimens and the strain gauge technique. In Ni-Cu alloys, both constants are negative irrespective of the composition and their absolute values decrease monotonously with increasing copper content. In Ni-Co alloys, the concentration dependence is quite different for λ_&tl;100> and λ_ ; λ_ is negative irrespective of the composition, showing a flat minimum centered at about 30% Co, while λ_ increases almost linearly with increasing cobalt content, passing through zero at about 20 % Co, and eventually reaches to a large value of 116×10^ at 55 % Co. It has been found that the experimental results on the concentration dependence of the magnetostriction constants of face-centered cubic Ni-Co alloys agree quite well with the Vonsovsky-Neel formula for binary cubic solid solutions consisting of two types of magnetic atoms A and B, which is of the form λ=C(N_A^2E_+2N_AN_BE_+N_B^2E_), where λ is λ_ or λ_, C the constant, N_A and N_B the concentrations of the A and B atoms, respectively, and E_, E_ and E_ the energies of magnetic interaction between A and A atoms, between A and B atoms, and between B and B atoms, respectively. For binary cubic solid solutions consisting of magnetic and non-magnetic atoms such as Ni-Cu alloys, it is shown theoretically and experimentally that the following relations hold approximately among the magnetostriction constants, saturation magnetization, I_s, and concentration of non-magnetic atoms, N : λ_∝ I_s^2∝ (1 -N/N_c)^2, where N_c is the concentration where the spontaneous magnetization disappears

Scanning electron microscopy of contactual interaction of sensitized lymphocytes with homologous target cells

Scanning electron microscope (SEM) observations were conducted mainly on the in vitro interaction state between ]TC-II cells derived from Ehrlich ascites tumor and regional lymph node cells obtained from the mice I0 days after transplantation of Ehrlich ascites tumor. Cells cultured on the cover glass were fixed with glutaraldehyde, dehydrated with graded acetone solution, and covered with carbon and gold, were observed by SEM. The results may be briefly summarized as follows. On the surface of ]TC.II cells themselves are seen numerous fine microvilli projecting out regularly at right angle to the cell surface, which become attached to the glass, and there can be observed vacuoles in the cytoplasm. Such microvilli are lacking at the tip of the pseudopodial projection. The lymph node cells aggregated to ]TC-II cell are lymphocytes of small or intermediate size, and the pattern of aggregation varies: some lymphocytes effect an intimate contact with the surface of target cell by their cellular projections; the contact is achieved by interdigitation of microvilli between lymphocyte and target cell; b:&#62;th cells form a bridge connection with a simple projection from each; or the two cells make a broad surface.to.surface contact. It is not possible to differentiate sensitized lymphocyte from nonsensitized one, their cell shape is spherical with rough surface and some cells show hole on the surface.</p

Homology of the adductor pollicis and contrahentes muscles: a study of monkey hands.

The deep palmar muscles in monkey hands were studied. The contrahentes muscles mainly arose from the capitate bone, descended palmar to the deep palmar branch of the ulnar nerve and the palmar metacarpophalangeal nerves, and attached to the proximal phalanges or wing tendons of the second, fourth and fifth fingers. In relation to the deep palmar branch of the ulnar nerve and the palmar metacarpophalangeal nerves, the contrahentes muscles are homologous with the adductor pollicis and flexor indicis radialis muscles. The contrahentes muscles occasionally gave off some accessory slips which blended with the interosseous muscles. These findings suggest that the human adductor pollicis muscle is a well-developed remnant of a contrahens muscle, and that the human interosseous muscles contain some remnant of the contrahentes muscle. In fact, a well-developed remnant of a contrahens muscle was found in the fourth finger of a human hand. It is further considered that the human adductor pollicis muscle contains an element of the interosseous muscle of the thumb.</p

Absence of scalenus anterior muscle.

A rare anomaly of the scalenus muscles is described. In this case, the right scalenus anterior muscle was absent. As a substitute for this muscle, some aberrant muscle slips arose from the lower vertebrae and descended in front of the ventral rami of the lower cervical nerves. These aberrant slips then ran between the ventral rami of the the eighth cervical and first thoracic nerves, and were fused with the right scalenus medius muscle. Thus, the subclavian artery and vein ran in front of the aberrant slips, together with the ventral ramus of the first thoracic nerve. The aberrant muscle slips issued 2 accessory bundles. One bundle ran between the ventral rami of the fourth and fifth cervical nerves and was fused with the scalenus medius muscle; the other bundle ran between the ventral rami of the fifth and sixth cervical nerves and was fused with the scalenus medius muscle.</p

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 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

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

Palmar interosseous muscle of the human thumb.

The adductor pollicis muscle was studied in fifty hands of Japanese adult cadavers of both sexes. The radial portion of the oblique head of the adductor pollicis muscle has carpal and metacarpal origins and an insertion into the wing tendon of the extensor apparatus. This portion was located dorsal to the palmar metacarpophalangeal articular nerve and superficial palmar metacarpal artery. Thus, the radial portion of the oblique head of the adductor pollicis muscle (more strictly, the slips dorsal to the palmar-penetrating twig of the ulnar nerve) is similar to the palmar interosseous muscles, except that its slips cannot be clearly distinguished from each other.</p