Heat Transfer Between Powdered CMN and Solid 3He in the Millikelvin Range
We present the results of heat transfer experiments between CMN and solid 3He from 4 to 30 mK. We have measured the recovery time τ after small magnetization-demagnetization cycles (H∿5–25 G). Our experimental cell contained 6.25 cm3 of bcc (24 cm3/mole) or liquid (29 bars) 3He and 22 g of powdered CMN (grain size < 40 μ, pores 1–5 μ). The 3He contained less than 50 ppm 4He which was not sufficient to cover the CMN surface (3.5 m2) with one 4He monolayer. Through the relaxation of the CMN susceptibility we observed the thermal recovery which appeared to be non exponential, probably due to the distribution in the powder size. τ is taken from the initial relaxation.
KeywordsThermal Recovery Heat Transfer Experiment Constant Resistance Thermal Boundary Resistance Initial Relaxation
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