Intersection point of magnetization curves in layered superconductors

It was claimed recently that the magnetization of underdoped LaSCO is not consistent with the theory based on the Lawrence-Doniach model. In particular, the intersection point of the magnetization curves moves in the opposite directions to that predicted theoretically. We define the intersection point and study it in detail. It is shown that the intersection point always occurs below T-c. The theory is shown to be in agreement with other recent experiments on layered superconductors on HgBCCO and LaSCO.