Abstract
A dilution refrigerator cryostat and high pressure cells have been constructed at Oak Ridge National Laboratory under the US-Japan Cooperation Program. The cryostat can produce the temperature down to 1.2 mK under the exposure of neutrons. Antiferromagnetic and sinusoidal arrangements of nuclear spins have been found in several enhanced magnetic systems. The high pressure cell produces the pressure of 2GPa at 4.2 K. Phonons observed under the isochoric condition which was realized by controlling the temperature and the pressure have revealed the deformation of phonons from a simple sinusoidal at high temperatures.
