The temperature dependence of the quadrupole interaction of100Rh in a Zn lattice

The¹⁰⁰Pd radioactivity was implanted into a pure Zn host with the help of an isotope separator. The temperature dependence of the quadrupole interaction was studied by time-differential measurements of the 84 keVγ- 75 keVK-conversion angular correlation. We conclude that electrons contribute significantly to the electric field gradient at the Rh site, but that local effects due to the 4d electrons of Rh are probably small.     

TDPAC experiments in111In-implanted niobium oxides

Magnetization and high field Mössbauer experiments were performed to study the ground state and the metamagnetic transition in Ce(Fe, Al)₂. A model is proposed for the arrangement of the Fe-moments which includes the reported finite Ce-moment.     

Temperature dependence of the electric field gradient at Ta nuclei in hafnium pyrovanadate

The electric field gradient EFG in hafnium pyrovanadate has been measured at Hf sites at different temperatures with the time-differential perturbed angular correlation method. The results obtained show the existence of a phase transition around 110°C.     

The electric quadrupole interaction of the 134 keV state of197Hg in the metal hosts Cd,Zn, Sn and Ti studied by e−-γ TDPAC measurements

The electric quadrupole coupling constants of the lowest excited 5/2^? state in¹⁹⁷Hg have been measured by the e^?-γ TDPAC method for the hosts Ti and Sn at room temperature and for Zn and Cd at various temperatures. The observed temperature dependences are approximately the same as those known for other impurities in the same host lattices. They are well described by a simpleT ^3/2 relation.     

Fibonacci, Van der Corput and Riesz-Nágy

What do the three names in the title have in common? The purpose of this paper is to relate them in a new and, hopefully, interesting way. Starting with the Fibonacci numeration system — also known as Zeckendorff's system — we will pose ourselves the problem of extending it in a natural way to represent all real numbers in (0,1). We will see that this natural extension leads to what is known as the ?-system restricted to the unit interval. The resulting complete system of numeration replicates the uniqueness of the binary system which, in our opinion, is responsible for the possibility of defining the Van der Corput sequence in (0,1), a very special sequence which besides being uniformly distributed has one of the lowest discrepancy, a measure of the goodness of the uniformity.Lastly, combining the Fibonacci system and the binary in a very special way we will obtain a singular function, more specifically, the inverse of one of the family of Riesz-Nágy.     

Hyperfine characterization of tin-doped indium sesquioxide

The hyperfine interactions at In and Sn sites of In₂O₃Sn (ITO) were measured through time-differential perturbed angular correlations and Mössbauer spectroscopy, respectively. Polycrystalline samples prepared by co-precipitation with nominal 0.025, 1 and 5 at.% Sn were studied. They all showed the cubic bixbyite structure characteristic of In₂O₃ after annealings at 200 °C. The quadrupole interaction at In sites appears nearly independent of Sn concentration being the main result of the presence of Sn in the lattice, the gradual disappearence of the dynamic perturbation caused by after-effects. The Mössbauer data demonstrate that Sn ions are in a 4+ state with Q=0.60₆ mm/s and=0.22₆ mm/s relative to SnO₃Ca at room temperature.     

Temperature dependence of the quadrupole interaction of100Rh in a Cd lattice

The quadrupole interaction frequency |v _q| = |eQV _zz /h|0 = 8.71 ± 0.11 MHz was measured for the 75 keV state of¹⁰⁰Rh in a polycrystalline cadmium matrix by use of the γ-e^? and γ-γ time differential perturbed angular correlation (TDPAC) techniques. The temperature dependence of the electric quadrupole coupling constant for¹⁰⁰Rh in Cd is similar to those of other impurities in Cd metal.     

Tdpac studies in the semiconductors SnO2 and Cu2O

We present here preliminary TDPAC results on the semiconductors SnO₂ and Cu₂O in the temperature range 17–1200K, using¹¹¹Cd. We discuss the presence of a time-dependent interaction associated to EC aftereffects processes in terms of the specific character (acceptor/donnor) of the impurity.     

TDPAC characterization of tin oxides using181Ta

In connection with a general study of the evolution of tin-oxygen thin films, we report here on the hyperfine interactions of¹⁸¹Ta substitutionally replacting tin in the isolated phases SnO and SnO₂. For this purpose, pure SnO pressed powder and a thin SnO₂ film were implanted with¹⁸¹Hf. In both cases, unique quadrupole frequencies were found after thermal annealing treatments. The results indicate that the following hyperfine parameters: υ _Q = 740.6(2.1) MHz, η=0.07(2) and υ _Q = 971.5(1.9) MHz, η=0.72(1) characterize¹⁸¹Ta in SnO and SnO₂, respectively.