Showing papers by "M. B. Maple published in 1976"
TL;DR: In this paper, the authors reported that the disappearance of superconductivity for x≳0.1 was correlated with a rapid decrease in the normal-state linear heat capacity coefficient.
Abstract: Heat capacity data are reported which confirm as a bulk effect the previously reported superconductivity in LiTi
2
O
4
. These data also establish LiTi2O4 as a weak couplingd-band superconductor with superconducting state properties well described by the Bardeen—Cooper—Schrieffer theory of superconductivity. The properties of LiTi
2
O
4
are compared with those of other superconducting spinel compounds, and the composition dependence ofT
c
for Li
1+x
Ti
2−x
O
4
is discussed. The disappearance of superconductivity forx≳0.1 was found to be correlated with a rapid decrease in the normal-state linear heat capacity coefficient.
110 citations
21 citations
TL;DR: In this paper, a T 3 2 contribution to both the heat capacity and the saturation magnetization of the weakly ferromagnetic compound UPt reveals the existence of spin waves in the Ferromagnetic state below the Curie temperature of 30 K. The entropy of ordering, extracted from calorimetric data on UPt and the isostructural nonmagnetic compound ThPt, is much smaller than the degeneracy entropy expected from the p ss″ e 5f3 (U3+) or 5f2(U4+) ionic configuration.
18 citations
01 Sep 1976
TL;DR: In this paper, the superconducting properties of matrix-impurity systems in three distinct regimes of magnetic character of the impurity which have been identified are reviewed, and the three regimes can be distinguished by the detailed behavior of the depressions of (1) the super-conducting transition temperature Tc as a function of impurity concentration n and (2) the specific heat jump ΔC at Tc, where ΔC is the function of Tc.
Abstract: The superconducting properties of exemplary matrix‐impurity systems in the three distinct regimes of magnetic character of the impurity which have been identified are reviewed. The three regimes can be distinguished by the detailed behavior of the depressions of (1) the superconducting transition temperature Tc as a function of impurity concentration n and (2) the specific heat jump ΔC at Tc as a function of Tc. These systematic s of superconductivity in the presence of local moments appear to be sufficiently well established that it is possible to (1) ascertain whether the solute spin is long‐lived (magnetic) or short‐lived (nonmagnetic) compared to thermal fluctuation lifetimes at superconducting temperatures, (2) determine the sign and magnitude of the conduction electron‐impurity spin exchange interaction parameter l and the temperature dependence of the exchange scattering of conduction electrons by long‐lived solute spins, (3) derive, in favorable cases, information pertaining to the energy level structure of rare earth ions in the crystalline electric field of their superconducting metallic host, and (4) observe magnetic‐nonmagnetic transitions of an impurity induced by the application of an external pressure or variation of the composition of a binary alloy matrix.
13 citations
01 Jan 1976
TL;DR: A lambda-type anomaly in the specific heat of the Chevrel phase compound Gd1.2Mo6Se8 has been observed at 3.5K, below its superconducting transition temperature of 5.5 K as mentioned in this paper.
Abstract: A lambda-type anomaly in the specific heat of the Chevrel phase compound Gd1.2Mo6Se8 has been observed at 3.5K, below its superconducting transition temperature of 5.5 K. The anomaly is not reflected in the temperature- or magnetic field-dependence of the magnetization, and low temperature X-ray powder diffraction measurements indicate that the anomaly is not due to a crystallographic phase transformation. The anomaly appears to be due to a phase transition which is associated with the presence of the localized 4f electrons of the Gd3+ ions, but the exact nature of the transition remains to be established.
7 citations
TL;DR: In this article, specific heat and magnetic susceptibility measurements are reported for a new metastable phase of scandium-chromium with the E9 3 crystal structure, which exhibits bulk type II superconductivity with an onset near 6.7 K.
3 citations
01 Jan 1976
TL;DR: In this paper, the authors discuss some related phenomena which may potentially be of technological use.Implanted solar wind plasma as a resource The solar corpuscular radiation that over billions of years has been implanted and stored in the lunar surface provides an important link in the record of the evolution of the Moon.
Abstract: Implanted solar wind plasma as a resource The solar corpuscular radiation that over billions of years has been implanted and stored in the lunar surface provides an important link in the record of the evolution of the Moon. The irradiation effects also give useful indications of the surface properties of solid grains in interstellar and circumstellar space. In the present context we will also discuss some related phenomena which may potentially be of technological use. The solar plasma flowing at i0 8 particles/cmasec, penetrate a few hundred _ into the exposed lunar dust and rocks. Erosion and mixing processes expose new material and bury irradiated particles so that a stratified sequence of lunar soil is formed. This sequence, containing the implanted solar wind, extends at least to the two-meter depth that has been sampled. Dust particles of less than one mm in size from highly-irradiated Apollo 15 soils release, on the average, 40 to 70 moles of hydrogen per ton and 5 to 9 of carbon upon heating to 1200°C (i., 2.,). Hydrogen release culminates around 600°C; carbon appears mainly in the form of carbon monoxide with small amounts of methane (0.i 8.0
TL;DR: In this article, low-temperature electrical resistivity measurements are reported for dilute alloys of Cu with approximately 100-ppm Mn which have been doped with Ni, Pd, and Pt additions at concentrations ranging from a few tenths to a few atomic percent.
Abstract: Low-temperature electrical-resistivity measurements are reported for dilute alloys of Cu with approximately 100-ppm Mn which have been doped with Ni, Pd, and Pt additions at concentrations ranging from a few tenths to a few atomic percent. Whereas Ni and Pt additions affect the temperature dependence of the resistance anomaly associated with the Kondo effect in a similar and striking fashion, Pd additions do not change the temperature dependence of the resistance anomaly within the resolution of the experiment. No correlation between the spin-orbit energy of the Ni, Pd, and Pt additions and the manner in which they modify the resistance anomaly could be established.