SQUID - high pressure I

We just got a set of easyLab system from our beloved collaborators in UNLV, which is designed for the Quantum Design SQUID. Here is the product information. (http://www.easylab.co.uk/productsdetails.asp?ID=12&iflgGreenSet=1)

Top left picture shows the high-pressure cell (Mcell 10) attached on the SQUID sample probe, and the top right picture shows the "Mpress" and pressure reader.

I have to say that, when cooling down the pressure cell in the SQUID, the cell keeps loosing from the top screw, and eventually falls off from the probe, even I use Mpress to tight it up to 50 N. Hence, the sample longitudinal scan is changing with time. Maybe I haven't find the trick to avoid it.

SQUID - ambient measurement.

Here is the traditional Quantum Design MPMS XL in our lab at the Glenn T. Seaborg Center at Lawrence Berkeley National Laboratory.

I have some experience on measuring small crystals loaded in a straw with two blocks of "quartz wall" (ambient pressure).

Since the magnetic correction is small for the "quartz wall", for most "magnetic" samples, the voltage vs. longitudinal length scan looks just like the diagrams shown in the users' manual.


However, to play the same measurement under high-pressure is not so easy, since we are going to use a "giant" pressure cell, which is composed of a few parts, and contributes a significant magnetic background to the data (1st order), the slow thermal reaction of the pressure cell maybe another problem that affects precision (2nd order).