Abstract: A second inclined surface (84c) which abuts against a recording disk of a chuck pawls (84) of a recording disk holding mechanism (80), and a third inclined surface (84d) which is a curved surface for guiding chucking motion of the chuck pawls (84) are provided. A boundary between the second inclined surface (84c) and the third inclined surface (84d) is formed with a stepped recess approaching a base.

Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.