ULTRA-HIGH MAGNETIC-FIELD EFFECT ON THE STRUCTURAL PHASE-TRANSITION IN (PB, GE)TE

Magnetic field effects on the structural phase transition in p-Pb1-xGe Te(x=0.01) and n-Pb1-xGexTe (x=0.008) have been investigated by infrar ed magneto-transmission measurements in the megagauss range using the single-turn coil technique. We have found that the transition temperat ure T(c) increases by 14 K by the application of magnetic fields of 90 T parallel to the [111] direction in p-type samples whose T(c) at 0 T is 34 K. Similar dependence has been observed in n-type samples. Thes e results not only provide a support to the previous work by Takaoka a nd Murase in the low field range below 7 T but also show that the magn etic field effect on the phase transition is even enhanced in the ultr a-high magnetic field range without any saturation. We have estimated the critical field of the possible structural phase transition induced by magnetic fields in PbTe.