QUANTUM HALL TRANSITIONS IN (TMTSF)(2)PF6

We have studied the temperature dependence of the integer quantum Hall transitions in the molecular crystal (TMTSF)(2)PF6. In the high-tempe rature regime, just below the transition temperature of the associated field-induced spin-density waves (FISDW), we find that the width of t he transitions between the quantum Hall plateaus, as measured by the s lope of the rho(xy) risers, d rho(xy)/dB, and the (inverse) width of t he rho(xx) peaks, (Delta B)(-1), decreases linearly with temperature; at low temperatures, however, the width saturates. We explain the temp erature dependence of the width in terms of that of the order paramete r of the FISDW and the characteristic impurity length scale of the sys tem.