We report on the electron and hole spin relaxation times in n-type and p-ty
pe CdMnTe quantum wells with nonmagnetic barriers measured via the time-res
olved magneto-optical Kerr effect in a pump-probe experiment, In addition t
o the decay of the Kerr effect at short pump-probe delays, we show that the
hole spin relaxation time may be also estimated from a phase shift induced
during the coherent rotation of the Mn spins, The variations of the spin r
elaxation times are studied as a function of Mn concentration, doping level
, and magnetic field applied parallel to the quantum well plane. The result
s show that the electron spin relaxation is dominated by the exchange scatt
ering with the Mn ions in the quantum well, and good agreement with theory
is obtained provided exciton effects are included. Relatively slow hole spi
n relaxation is observed in the p-type samples (hole spin lifetime up to 32
ps) as compared to published values for similar diluted magnetic II-VI het
erostructures.