Thermal Conductivity of a Gas of Rotating Diamagnetic Molecules in an Applied Magnetic Field

The effect of an applied magnetic field on the thermal conductivity of a gas of rotating diamagnetic molecules is determined with the rotational states treated quantum mechanically. The anisotropic part of the thermal conductivity tensor λ is given in terms of square-bracket integrals and the ratio of the magnetic field H to the equilibrium pressure p of the gas. The square-bracket integrals to be determined are expressed in terms of reduced relative and center-of-mass velocities. The ratio of the saturation values of the anisotropic thermal conductivity when the applied field is parallel to and perpendicular to the temperature gradient is found to be ⅔. Also, a transverse heat flux or Righi—Leduc effect for gases is discussed briefly, and shown to vanish at infinite and zero fields, attaining a maximum somewhere between.