THE PRODUCTION OF TEMPERATURES BELOW 1 DEGREE K BY THE ADIABATIC DEMAGNETIZATION OF 50% CE(PO3)3-BA(PO3)2 GLASS.
NAVAL RESEARCH LAB WASHINGTON D C
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It was the object of the investigation to determine whether cerium metaphosphate glass specifically 50 by weight CePO33-BaPO32 is a suitable coolant material for adiabatic demagnetization experiments. Cerium glass is not susceptible to dehydration and attack by glycerine used for thermal contact as are many of the hydrated salts. In addition, the concentration of magnetic atoms can be varied over a wide range by diluting the magnetic glass CePO33 with the nonmagnetic glass BaPO32. The principal results of this investigation are a the 50 CePO33-BaPO32 glass was successfully cooled many times by adiabatic demagnetization, and magnetic temperatures as low as 0.0069K were reached, b using a cerium magnesium nitrate paramagnetic salt as a thermometer, absolute temperatures as low as 0.02K were observed, and c within experimental error, the measured Curie constant for the cerium glass density 3.57 agrees with that calculated from the Brillouin function for J 12 and 1.97 or g or 2.00. Author
- Solid State Physics