Magnetic Susceptibility of High-Purity Thorium

Abstract

The magnetic susceptibility of thorium has been measured between 18 and 328 \ifmmode^\circ\else\textdegree\fi{}K. The thorium samples had been refined by the electrotransport process and had electrical resistivity ratios ranging between 790 and 1300. Linear extrapolation of the data to 0 \ifmmode^\circ\else\textdegree\fi{}K yields a value of + 0.383 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}6}$ emu/g. This susceptibility increases nearly linearly with increasing temperature to (+ 0.412 \ifmmode\pm\else\textpm\fi{} 0.001) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}6}$ emu/g at 300 \ifmmode^\circ\else\textdegree\fi{}K. This behavior is qualitatively consistent with the behavior of a number of other physical properties and implies a temperature-dependent electronic distribution in thorium metal.