The combined effects of uniform thermal and magnetic fields on the propagation of plane waves in a homogeneous, initially unstressed, electrically conducting elastic medium have been investigated.

When the magnetic field is parallel to the direction of wave propagation, the compression wave is purely thermo-elastic and the shear wave is purely magneto-elastic in nature. For a transverse magnetic field, the shear waves remain elastic whereas the compression wave assumes magneto-thermo-elastic character due to the coupling of all the three fields—mechanical, magnetic and thermal. In the general case, the waves polarized in the plane of the direction of wave propagation and the magnetic field are not only coupled but are also influenced by the thermal field, once again exhibiting the coupling of the three fields. The shear wave polarized transverse to the plane retains its magneto-elastic character.

Notation.

Hi = primary magnetic field components,

ht = induced magnetic field components,

To = initial thermal field,

θ = induced thermal field,

C = compression wave velocity.

S = shear wave velocity,

ui = displacement components,

cv = specific heat at constant volume,

k = thermal conductivity,

η = magnetic diffusivity,

μe = magnetic permeability,

λ, μ = Lamé's constants,

β = ratio of coefficient of volume expansion to isothermal compressibility.