54 research outputs found
Synthesis, characterization, and phase relations of Zinc-Rich phases in the binary systems Platinum-Zinc and Nickel-Zinc
Synthesis, characterization, and phase relations of Zinc-Rich phases in the binary systems Platinum-Zinc and Nickel-Zinc
Synthesis, characterization, and phase relations of Zinc-Rich phases in the binary systems Platinum-Zinc and Nickel-Zinc
Synthesis, characterization, and phase relations of Zinc-Rich phases in the binary systems Platinum-Zinc and Nickel-Zinc
Structural and ferromagnetic properties of an orthorhombic phase of MnBi stabilized with Rh additions
The article addresses the possibility of alloy elements in MnBi which may
modify the thermodynamic stability of the NiAs-type structure without
significantly degrading the magnetic properties. The addition of small amounts
of Rh and Mn provides an improvement in the thermal stability with some
degradation of the magnetic properties. The small amounts of Rh and Mn
additions in MnBi stabilize an orthorhombic phase whose structural and magnetic
properties are closely related to the ones of the previously reported
high-temperature phase of MnBi (HT~MnBi). To date, the properties of the
HT~MnBi, which is stable between and ~K, have not been studied in
detail because of its transformation to the stable low-temperature MnBi
(LT~MnBi), making measurements near and below its Curie temperature difficult.
The Rh-stabilized MnBi with chemical formula MnRhBi
[] adopts a new superstructure of the NiAs/NiIn structure
family. It is ferromagnetic below a Curie temperature of ~K. The critical
exponents of the ferromagnetic transition are not of the mean-field type but
are closer to those associated with the Ising model in three dimensions. The
magnetic anisotropy is uniaxial; the anisotropy energy is rather large, and it
does not increase when raising the temperature, contrary to what happens in
LT~MnBi. The saturation magnetization is approximately ~/f.u. at low
temperatures. While this exact composition may not be application ready, it
does show that alloying is a viable route to modifying the stability of this
class of rare-earth-free magnet alloys.Comment: 9 pages, 10 figure
Liquid/Single Crystal Structure Analysis: Synthesis and Characterization of a Trimethylsilyl Derived Rod Shaped Mesogen
4-[4’-Cyanophenoxy-carbonyl-phenyl-4-(trimethylsilyl)ethynyl]benzoate a rod shaped liquid crystal (SmA) is synthesized and characterized. The single-crystals were grown in triclinic crystal system in the space group of Pi - with unit cell parameters a = 5.9577(2) Å, b = 8.0398(3) Å, c = 25.8842(9) Å, a = 86.096(2)o , ß = 89.912(2)o , ? = 2.919(2)o , Z = 2, and V = 1182.16(7). The crystal structure is stabilized by C–H···O intra-molecular interactions. Further, the structure also involves C–H···p interactions and weak p–p stacking interactions [centroid–centroid separation = 3.806 (3) Å
Hydrostatic pressure study of single-crystalline UNi0.5Sb2
We studied single-crystals of the antiferromagnetic compound UNi0.5Sb2 (TN ~
161 K) by means of measurements of magnetic susceptibility (chi), specific heat
(Cp), and electrical resistivity (rho) at ambient pressure, and resistivity
under hydrostatic pressures up to 20 kbar, in the temperature range from 1.9 to
300 K. The thermal coefficient of the electrical resistivity (drho/dT) changes
drastically from positive below TN to negative above, reflecting the loss of
spin-disorder scattering in the ordered phase. Two small features in the rho vs
T data centered near 40 and 85 K correlate well in temperature with features in
the magnetic susceptibility and are consistent with other data in the
literature. These features are quite hysteretic in temperature, i.e., the
difference between the warming and cooling cycles are about 10 and 6 K,
respectively. The effect of pressure is to raise TN at the approximate rate of
0.76 K/kbar, while progressively suppressing the amplitude of the small
features in rho vs T at lower temperatures and increasing the thermal
hysteresis.Comment: 9 pages, 3 figues, 2007-mmm conferenc
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