A particulate medium oriented longitudinally inside and perpendicularly at surface (LIPS)

A LIPS tape of CrO2particles was prepared through the follwing steps: 1) a perpendicular orientation over the entire thickness by the previous "VAST" method (Vertical magnetic orientation-AC demagnetization-Smoothing period -Train), 2) a short radiation heating only in the shallow surface layer and 3) a magnetic reorientation to the longitudinal direction only in the inside layer, still in a low viscosity state. Their magnetic data show that the thickness of the perpendicular surface layer can be controlled to any suitable thin value by the heating condition. Their wavelength response shows both high density and wide band characters.