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Behavior Of Grain Boundary Resistivity In Metals Predicted By A Two-Dimensional Model, Rand Dannenberg, Alexander H. King
Behavior Of Grain Boundary Resistivity In Metals Predicted By A Two-Dimensional Model, Rand Dannenberg, Alexander H. King
Alexander H. King
The behavior of a model for the specific grain boundary resistivity in metallic bamboo conductor lines is developed and compared to other theoretical treatments, and to experiment. The grain boundary is modeled as an array of scatterers on a plane. The scatterers are called “vacancy-ion” complexes, in which the vacancy represents the boundary free volume, and the ion is an atom adjacent to the vacancy. Three cases are investigated, that of noninterfering scatterers, a continuum of interfering scatterers, and discrete interfering scatterers. The approximations used lead to a specific grain boundary resistivity ∼10−16 Ω m2 for aluminum, in agreement with …
Resistivity, Thermopower And The Correlation To Infrared Active Vibrations Of Mn1.56co0.96ni0.48o4 Spinel Films Sputtered In An Oxygen Partial Pressure Series, Rand Dannenberg, S. Baliga, R. J. Gambino, Alexander H. King, A. P. Doctor
Resistivity, Thermopower And The Correlation To Infrared Active Vibrations Of Mn1.56co0.96ni0.48o4 Spinel Films Sputtered In An Oxygen Partial Pressure Series, Rand Dannenberg, S. Baliga, R. J. Gambino, Alexander H. King, A. P. Doctor
Alexander H. King
Mn1.56Co0.96Ni0.48O4 spinel was sputter deposited using a series of oxygen partial pressures. Electrical resistivity versus temperature and thermopower versus temperature measurements at each oxygen partial pressure were made. The variations of the thermopower and resistivity with oxygen partial pressure are consistent with a change in the ratio of Mn3+ to Mn4+ cations, which occurs due to changes of oxygen content of the material. The weak temperature dependence of the thermopower indicates small polaron hopping is the charge transport mechanism. Combining the models of Mott and Schnakenberg to analyze the transport data, we find that the Debye temperature (or frequency) is …
Low‐Temperature Phase Diagram Of Ybbipt, R. Movshovich, A. Lacerda, Paul C. Canfield, J. D. Thompson, Z. Fisk
Low‐Temperature Phase Diagram Of Ybbipt, R. Movshovich, A. Lacerda, Paul C. Canfield, J. D. Thompson, Z. Fisk
Paul C. Canfield
Resistivity measurements are reported on the cubic heavy‐fermion compound YbBiPt at ambient and hydrostatic pressures to ≊19 kbar and in magnetic fields to 1 T. The phase transition at T c =0.4 K is identified by a sharp rise in resistivity. That feature is used to build low‐temperature H‐T and P‐Tphase diagrams. The phase boundary in the H‐T plane follows the weak‐coupling BCS expression remarkably well from T c to T c /4, while small hydrostatic pressure of ≊1 kbar suppresses the low‐temperature phase entirely. These effects of hydrostatic pressure and magnetic field on the phase transition are consistent with …
Magnetism And Heavy Fermion‐Like Behavior In The Rbipt Series, Paul C. Canfield, J. D. Thompson, W. P. Beyermann, A. Lacerda, M. F. Hundley, E. Peterson, Z. Fisk, H. R. Ott
Magnetism And Heavy Fermion‐Like Behavior In The Rbipt Series, Paul C. Canfield, J. D. Thompson, W. P. Beyermann, A. Lacerda, M. F. Hundley, E. Peterson, Z. Fisk, H. R. Ott
Paul C. Canfield
Members of the RBiPt (R=Ce–Lu with the exceptions of Pm and Eu) series have been grown as single crystals.Magnetic susceptibility and electrical resistance have been measured on all members of the series, and specific heatmeasurements have been performed on representatives. The high temperature resistance uniformly changes from that of a small‐gap semiconductor or semimetal seen in NdBiPt to that of a heavy‐fermion metal seen in YbBiPt, which shows a linear coefficient of specific heat at low temperatures of 8 J/K2 mole. Further, the lighter rare earth members show an unusually sharp increase in their resistance associated with antiferromagnetic ordering at …