Transport properties and the large anisotropic magnetoresistance of CuxNbS2 single crystals
The transport properties of CuxNbS2 (x = 0.09, 0.44 and 0.55) single crystals were systematically studied. The in-plane and out-of-plane resistivities decrease with increasing Cu content, and a transition with hysteresis shows up for the crystals with x = 0.44 and 0.55. The thermopower and Hall coefficient of CuxNbS2 show opposite signs, indicating that there are two kinds of carriers in this system. The angular dependences of the in-plane magnetoresistance (MRab = (ρab(H)−ρab(0))/ρab(0) × 100%) at different temperatures were also studied. The single crystals with x = 0.44 and 0.55 show a strong anisotropic MRab. For the x = 0.55 sample, MRab reaches 80% with a magnetic field of 14 T applied along the c-axis, while MRab is less than 5% for the magnetic field applied within the ab-plane. These results can be well understood in the light of the anisotropic Fermi surface in the multiband system.
Non-uniform doping across the Fermi surface of NbS2 intercalates
Abstract.Magnetic ordering of the first row transition metal
intercalates of NbS2 due to coupling between the conduction
electrons and the intercalated ions has been explained in terms of
Fermi surface nesting. We use angle-resolved photoelectron
spectroscopy to investigate the Fermi surface topology and the
valence band structure of the quasi-two-dimensional layer compounds
Mn1/3NbS2 and Ni1/3NbS2. Charge transfer from the
intercalant species to the host layer leads to non-uniform, pocket
selective doping of the Fermi surface. The implication of our
results on the nesting properties are discussed.


Effects of Equipment Dimensions on Liquid Mixing Time of Bubble Column with Draft Tube
The liquid mixing time of a bubble column with a draft tube is experimentally studied. The diameter and height of the column, the diameter and length of the draft tube, and the mode of sparging gas were changed and the liquid mixing time was measured.The lengths of bottom and top clearances have significant effects on the liquid mixing time. The liquid mixing time increases with increasing column aspect ratio of height to diameter. The liquid mixing time of the bubble column with a draft tube is longer than that of a standard bubble column when the column aspect ratio is relatively high. The liquid mixing time has a minimum when the diameter ratio of draft tube to column is 0.5 to 0.6. These effects of equipment dimensions are expressed by an equation. In the experiment using different solutions, the liquid mixing time becomes shorter with increasing liquid surface tension, or with increasing liquid viscosity.