The Magnetic Susceptibilities of Platinum, Rhodium and Palladium from 20 to 290 degrees K

摘要: An apparatus is described which makes possible the rapid determination of temperature variation magnetic susceptibilities small solid specimens. The deflexions a beam light passing through Sucksmith balance are recorded photographically. specimen, measured by Au-Co/Ag-Au thermocouple in contact with it, initially reduced to 20° K and at intervals as specimen rises 290° K. whole range can be covered 4 h. mean deviation single measurements from best smooth curve them less than 0.2 % mass susceptibility has been used measure spectrographically standardized specimens platinum, rhodium palladium. Measure­ments on three pure palladium show maximum 80° experimental results for platinum change curvature below 90° K, increasing more rapidly decreases. regular increase temperature. discussed relation collective electron treatment metals, assuming parabolic distribution energy states d band, estimates made effective Fermi-Dirac degeneracy θ F , number holes per atom, q exchange interaction θ9 . estimated values = 1020° 0.29, 554.0° Similar case being =1750° 0.25, 770°