Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material {containing non-metallic substances iron oxides gamma - Fe2 O3 containing a dopant containing Co}
Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material {containing non-metallic substances iron oxides gamma - Fe2 O3 containing a dopant containing Co}