Yasumitsu Matsuo

New Stage Structure of Iodine Doped Pentacene Film (II)

Abstract In pure pentacene film and iodine doped pentacene film, X-ray and electric conductivity measurements were performed. It was found from X-ray diffraction data that the iodine doped pentacene possess the stage-2 structure in addition to the stage-1 structure. The c axis lattice constant of the stage-2 structure, which is the length of the interval between the layers, was determined to be 33.2 Å. Moreover, electric conductivity was measured in pentacene doped with iodine at the various doping temperatures T d. This result was compared with the results obtained from X-ray diffraction data.

1 H-NMR on Super-Ionic Conductor TI 3 H(SO 4 ) 2

We have studied the proton dynamics on Tl 3 H(SO 4 ) 2 from the measurements of 1 H-NMR absorption lines. It was found that the NMR line width j H at room temperature becomes about 20 times narrower than that at 77 K and that the NMR absorption line at room temperature shows the mixture functional form of the Gaussian and Lorentzian. These results indicate that protons migrate even at room temperature: that is, Tl 3 H(SO 4 ) 2 becomes a super-ionic conductor at room temperature. From the temperature dependence of j H , we have obtained the result that the phase transition at T II-III = 239 K corresponds to the super-ionic phase transition. Furthermore, we calculate the proton correlation times from the line widths and determine the activation energy of proton motion in the phase II (super-ionic phase) to be 0.33 eV. This result indicates that proton migration lead to the electric conductivity in the super-ionic phase.

New stage structure of iodine doped pentacene film

The iodine doped pentacene films have been prepared using the two bulb method. The X-ray diffraction studies show that the iodine doped pentacene possess the so-called second stage structure in addition to the first stage structure. The typical doping temperature to obtain the second stage structure is 5.2°C. From this result, the c axis lattice constant of the second stage structure, which is the length in the interval in the layer, was determined to be 33.2 A.

NMR study on dynamics of protons in Rb3H(SeO4)2

Abstract Proton NMR spectra were measured in the region from 300K to 500 K, in order to clear the proton dynamics in the a h-b h plane of hexagonal system in paraelastic phase for Rb3H(SeO4)2, directly. It was found from the NMR spectra that the hydrogen bonds between SeO4ions should be broken with the rearrangement process in the a h−b h plane above Tc . Moreover, from the analysis of the second and forth moments, we determined the area of proton motion in the a h-b h plane.

NMR Study on (CH 3 ) 2 NH 2 H 2 AsO 4

Proton NMR line width and spin-lattice relaxation time T 1 for the ferroelectric (CH 3 ) 2 NH 2 H 2 AsO 4 have been measured at the temperature range between 77 K and 300 K. The temperature dependence of T 1 is well described by the expressions based on rotation of the methyl group using the value of activation energy E a = 99 meV and elementary correlation time 0 = 1.5 2 10 m 13 sec. Moreover, a sharp dip of T 1 near ferrroelectric phase transition temperature ( T c = 274.5 K) results from the ordering of protons. In addition, the temperature dependence of T 1 deviates from the expression for molecular rotation above around 200 K. It is deduced that the deviation is caused by the suppression of some kind of proton motion.