Magneto-optical recording medium

A magneto-optical recording medium comprising:

• a reproducing layer whose magnetization direction is in-plane at room temperature and shifts to perpendicular at a predetermined temperature Ttrans and at temperatures above said predetermined temperature Ttrans.;
• a recording layer whose magnetization direction is perpendicular in a range between room temperature and a Curie temperature thereof, during which said recording layer being magneto-statically coupled to said reproducing layer;
• a magnetic mask layer which is provided between said reproducing layer and recording layer with an intermediate layer on said reproducing layer side, and whose magnetization direction is in-plane at room temperature,
• magnetization of said magnetic mask layer being (a) larger than magnetization of said recording layer at least in a range between room temperature and said predetermined temperature Ttrans., (b) smaller than magnetization of said recording layer at or above a predetermined temperature exceeding said predetermined temperature Ttrans, and (c) reduced to 0 (zero) at Tm, wherein Tm is a predetermined temperature that is at least as high as Ttrans.

A magneto-optical recording medium comprising:

• a reproducing layer whose magnetization direction is in-plane at room temperature and shifts to perpendicular at a predetermined temperature Ttrans and at temperatures above said predetermined temperature Ttrans;
• a recording layer whose magnetization direction is perpendicular in a range between room temperature and a Curie temperature thereof, during which said recording layer being magneto-statically coupled to said reproducing layer;
• a magnetic mask layer which is provided between said reproducing layer and recording layer with an intermediate layer on said reproducing layer side, and whose magnetization direction is in-plane at room temperature,
• wherein said magnetic mask layer is made of an alloy of Nd and Fe, and wherein the magnetic mask layer alloy has a composition of NdxFe100−x, wherein x is in a range 6.0≦x≦10.5 (at %).

A magneto-optical recording medium comprising:

• a reproducing layer whose magnetization direction is in-plane at room temperature and shifts to perpendicular at a predetermined temperature Ttrans. and at temperatures above said predetermined temperature Ttrans.;
• a recording layer whose magnetization direction is perpendicular in a range between room temperature and a Curie temperature thereof, during which said recording layer being magneto-statically coupled to said reproducing layer;
• a magnetic mask layer which is provided between said reproducing layer and recording layer with an intermediate layer on said reproducing layer side, and whose magnetization direction is in-plane at room temperature,
• wherein said magnetic mask layer is made of alloy of Nd, Fe and Ni, and
• wherein the magnetic mask layer alloy has a composition of Nd.(FeyNi100−y)100−x
• wherein x is in a range 5.0 <x <10.5 (at %) and y is in a range 5.0 <y <70.0 (at %).

A magneto-optical recording medium comprising:

• a reproducing layer whose magnetization direction is in-plane at room temperature and shifts to perpendicular at a predetermined temperature Ttrans and at temperatures above said predetermined temperature Ttrans;
• a recording layer whose magnetization direction is perpendicular in a range between room temperature and a Curie temperature thereof, during which said recording layer being magneto-statically coupled to said reproducing layer;
• a magnetic mask layer which is provided between said reproducing layer and recording layer with an intermediate layer on said reproducing layer side, and whose magnetization direction is in-plane at room temperature,
• said magnetic mask layer being made of alloy including at least one kind of light rare earth metals and at least one kind of 3d transition metals,
• wherein magnetization of said magnetic mask layer is reduced to 0 (zero) at or above predetermined temperature Tm, wherein ((Ttrans)−80(° C.))≦Tm.