The pressure dependence of the spin reorientation in Er
2Fe
17C
2 was measured by means of ac initial susceptibility under 1-12 kbar. As a result, the spin reorientation temperature shifted toward the higher side with increasing pressure. From this experimental observation it is believed that the pressure increases the anisotropy energy of the rare earth. That is, the pressure effect is equal to increasing the absolute value of the negative second-order crystalline field coefficient
A20![](/images/glyphs/BDK.GIF)
. The
change in
A20 is estimated to be reasonable from the value of
Young's modulus of Er
2Fe
17.