Authors:F. Ambe, Y. Ohkubo, S. Ambe, Y. Kobayashi, T. Okada, Y. Yanagida, J. Nakamura, K. Asai, Y. Kawase, and S. Uehara
The features of time-differential perturbed angular correlation (TDPAC) in studies on local chemical structures around impurity atoms are described in comparison with those of Mössbauer emission spectroscopy with four typical examples of recent applications to metal oxide systems, namely,99Rh
99Ru in -Fe2O3 and YBa2Cu3O7– and117Cd
117In in MO (M=Mn, Co, Ni) and BaRu2/3Cd1/3O3.
Authors:S. Ambe, S. Chen, Y. Ohkubo, Y. Kobayashi, H. Maeda, M. Iwamoto, M. Yanokura, N. Takematsu, and F. Ambe
We established Multitracer, a new versatile radiotracer technique, for simultaneous tracing of a number of elements in various chemical, environmental, and biological systems. Metal foil targets (typically Au, Ag, Ge, Cu and Fe) are irradiated with C, N, or O ions accelerated up to 135 MeV/nucleon by RIKEN Ring Cyclotron. Radiochemical procedures have been developed to remove the target material leaving the nuclides as Multitracer solutions containing various radionuclides of Be, Na, Mg, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Te, I, Ba, Ce, Pm, Eu, Gd, Tb, Tm, Yb, Lu, Hf, W, Re, Os, Ir, Pt, and Hg. Multitracers enable efficient tracing of a number of elements, and comparison of their behavior under strictly identical experimental conditions. Such features will be demonstrated by means of an example of application to a model experiment for the study of removal mechanism of various elements from the ocean.
Authors:Y. Kobayashi, M. Katada, H. Sano, T. Okada, K. Asai, and F. Ambe
99Ru and57Fe-Mössbauer spectroscopic and magnetization measurements were made in order to clarify the magnetic properties of a Huesler alloy, RuFe2Si. The result obtained from99Ru-Mössbauer spectrum leads to the conclusion that Ru atoms were substituted by both Fe[A, C] and Fe[B], but the latter preferentially.
Authors:W. Sato, K. Sueki, K. Kikuchi, K. Kobayashi, S. Suzuki, Y. Achiba, H. Nakahara, Y. Ohkubo, F. Ambe, and K. Asai
Time-differential perturbed angular correlation method was applied to Ce@C82 in order to investigate the electronic properties of the encaged Ce atom. The nuclear quadrupole frequency of the nuclear
spin of the Ce was successfully determined as ωQ = 6.5(3)·107 rad/s, which is much greater than what has already been estimated for Ce4+ and La3+ in other compounds. By comparing the present value with the values for the Ce4+ and La3+, it was inferred that the valence state of the encaged Ce atom is trivalent.