Showing papers by "M. B. Maple published in 1975"
TL;DR: In this article, heat capacity measurements between 0.07 and 20 K and 0 and 38 kOe are reported for the system ( La Ce)Al2, where the crystal-field ground state of the Ce ion is a doublet.
49 citations
TL;DR: In this paper, a detailed measurement of the variation of the superconducting transition temperature, Te with Pr impurity concentration, N, and the dependence of the specific heat jump deltac at T/sub c/ on T/ sub c/ have been made and compared with the predictions of Fulde.
Abstract: Detailed measurements of the variation of the superconducting transition temperature, Te with Pr impurity concentration, N, and the dependence of the specific heat jump deltac at T/sub c/ on T/sub c/ have been made and compared with the predictions of Fulde. The calculations required determined the Pr energy level scheme from measurements of Schottky heat capacity anomaly and the Pr ion contribution to the Van Vleck paramagnetic susceptibility. The agreement between calculated and measured superconducting properties supported Fulde's supposition of two mechanisms (pairing and depairing) whereby the matrix properties are modified by the paramagnetic impurity. 10 references.
49 citations
TL;DR: In this article, high field magnetization of a sample of ZrZn 1.9 was measured at pressures up to 20 kbar and the Curie temperature T 0 drops linearly from 27.6 to 9.1°K; it then curves downward and crosses the T 0 = 0 axist at critical pressure p c of 18 kbar.
47 citations
TL;DR: In this paper, the weak ferromagnetic saturation moment of the intermetallic compound UPt is reduced with respect to the atmospheric pressure value by more than 90% at 20 kbar.
30 citations
TL;DR: In this article, specific measurements of the specific heat jump ΔC at the superconducting transition temperatureTc as a function of Tc are reported for several (La, Th)Ce systems.
Abstract: Detailed measurements of the specific heat jump ΔC at the superconducting transition temperatureTc as a function ofTc are reported for several (La, Th)Ce systems. The measurements document the continuous demagnetization of the Ce impurity ions which proceeds with increasing Th concentration, and provide a critical test of a theory recently developed by Muller-Hartmann and Zittartz for the superconducting behavior of matrix-impurity systems which simultaneously exhibit both superconductivity and the Kondo effect.
26 citations
TL;DR: In this paper, the specific heat jump ΔC at the superconducting critical temperature Tc on (Th, Sc )Ce and ( Th, Y )]Ce impurity, solid solution alloy systems indicate that the former systems obey the BCS law of corresponding states (LCS) characteristic of superconductors with non-magnetic impurities while the latter systems present deviations from the LCS linear relation between reduced parameters which are attributed to the development of localized moments at the Ce ions as the Y concentration increases.
5 citations
01 Jan 1975
TL;DR: In this paper, the magnetic susceptibility data for the (La,Th)Ce system were analyzed and the effect of pressure on the low temperature resistivity anomaly due to the Kondo effect was investigated.
Abstract: Measurements of the magnetic susceptibility as a function of temperature are reported for the (La,Th)Ce system which document directly the continuous demagnetization of Ce impurities which proceeds with increasing Th composition.Ce impurities can undergo a continuous magnetic‐nonmagnetic transition when the matrix into which they have been dissolved is subjected to an external pressure or alloyed with another element.1 This effect was first observed during an experimental investigation of the pressure dependence of the superconducting transition temperature Tc of LaCe and related systems.2 Subsequently, the effect of pressure on the low temperature resistivity anomaly ρm(T) due to the Kondo effect in the LaCe system was independently studied by two groups.3,4 Unfortunately, experimental difficulties attendant to measurements at high pressure have so far prevented the acquisition of other data on this interesting system.It was later found that the continuous demagnetization of Ce impurities could also be induced by alloying the La matrix with increasing amounts of Th.5 This afforded the opportunity to measure various important physical parameters related to the demagnetization of Ce impurities in a matrix at zero applied pressure. Since then, extensive data have been accumulated for the depression of Tc with Ce concentration n,6 the depression of the specific heat jump ΔC at Tc with Tc,7 and ρm(T)8 as a function of La,Th host composition. In this paper we present magnetic susceptibility data for the (La,Th)Ce system which document the continuous demagnetization of the Ce ion directly.
3 citations