  Experimental evidence of the anisotropy of the magnetic deflagration
associated with the low-temperature first order antiferromagnetic (AFM) -->
ferromagnetic (FM) phase-transition in single crystals of Gd5Ge4 is reported.
The deflagrations have been induced by controlled pulses of surface acoustic
waves (SAW) allowing us to explore both the magnetic field and temperature
dependencies on the characteristic times of the phenomenon. The study was done
using samples with different geometries and configurations between the SAW
pulses and the direction of the applied magnetic field with respect to the
three main crystallographic directions of the samples. The effect of
temperature is nearly negligible, whereas observed strong magnetic field
dependence correlates with the magnetic anisotropy of the sample. Finally, the
role of the SAW pulses in both the ignition and formation of the deflagration
front was also studied, and we show that the thermal diffusivity of Gd5Ge4 must
be anisotropic, following \kappaa>\kappab>\kappac.
