SPIN SUSCEPTIBILITY BEHAVIOR IN THE BI2SR2CAN-1CUNO2N- FROM UNDERDOPED TO OVERDOPED REGIME(4 COMPOUNDS )

We have studied the thermal behaviour of the spin susceptibility, chi, (spin)(T), of the CuO2 planes in the normal phase. chi,(spin)(T) was m easured by O-17 and Ca-43 NMR in various compounds of the Bi2Sr2Can-1C unO2n+4 family : a n=3 sample almost optimally doped, an overdoped n=2 sample and a more strongly doped n=1 sample. By contrast to the under doped case, in the overdoped one, chi,(spin)(T) increases when cooling . Furthermore, this behaviour is enhanced by increasing the doping. ch i,(spin)(T) is compared to the macroscopic susceptibility behaviour. O n the other hand, our results are consistent with a decrease of the nu mber of charge carriers per copper plane for increasing n.