High Resolution Neutron Spectrometer LAM-80ETand Rotational Tunnelling in 4-Methylpyridine N-Oxide

摘要: A high energy-resolution neutron spectrometer with large mica mirrors, LAM-80ET, has been constructed at National Laboratory for High Energy Physics in Japan (KEK). The highest resolution achieved this is 1.2 µeV. In order to examine the capability of spectrometer, rotational tunnelling methyl group 4-methyl pyridine N-oxide (N-oxy γ-picoline) measured. Using (004) reflection we have clearly observed four peaks e=60, 115, 190 and 274 Measurements Q -dependence these show that potential may be three-fold. It also shown line width modes spin conversion T >5 K are derived by libron-phonon process E L =30-40 K.