MINIATURE DIAMOND-ANVIL CELL FOR ELECTRICAL-TRANSPORT MEASUREMENTS INHIGH MAGNETIC-FIELDS

The combination of high magnetic fields and high pressures offers many interesting avenues of exploration to the physics community. To facil itate these measurements, we have developed a diamond-anvil cell, cryo genic loader, and goniometer system which allow us to orient a pressur ized sample with respect to a magnetic field while in a cryogenic envi ronment. The cell, reported in this paper, has provisions for eight mi cro-mini triax cables which allow one to perform a variety of electric al transport measurements including studies of anisotropic materials. Optical access, f/3, is provided through the diamonds for pressure cal ibration and any variety of optical studies. The cell, constructed ent irely of BeCu, can rotate freely in a cryostat with an inner diameter greater than 20.3 mm while keeping the pressurized sample space within the central 1-cm3 sphere of magnetic homogeneity typical of most magn ets. Using this cell, we have monitored the second harmonic in the non linear optical material KTP to 7.3 GPa and observed the pressure-induc ed first-order phase transition at 5.77 GPa using 0.95-mm culets and l iquid helium as a pressure medium.