Abstract: A method of testing memory of a system is disclosed which operates the system from a second area of system address space which is outside of a first area of system address space, the system having one or more physical memory devices associated with the first area of system address space. The memory locations associated with the first area of the system address space are tested for predetermined characteristics after which the one or more tested physical memory devices are replaced with respective untested physical memory devices without dropping power to the system, and tested by repeating the test cycle. The system is prevented from operating in the first area of system address space and forced to operate from the second area, thereby preventing system interruptions when replacing the physical memory devices for testing.

Abstract: A seed layer is deposited under an underlayer in magnetic thin film media. The seed layer material has a similar lattice parameter and a similar crystal structure to the underlayer material. The preferred structure involves a nickel-aluminum seed layer, under a chromium underlayer, under a cobalt-based magnetic layer. Use of the nickel-aluminum seed layer produces higher coercivity and lower media noise in the resultant magnetic thin film. The coercivity and media noise values for the resultant magnetic thin film are dependent upon deposition parameters, and recommended deposition parameters are given.

Abstract: The signal-to-noise ratio of a magnetic recording medium having a thin magnetic layer is improved by adjusting the deposition conditions of the underlayer so that the magnetic layer is pseudo-epitaxially grown with a substantially uniform sub-micron-scale morphology. Uniform sub-micron-scale morphology can be attained by strategic selection of the underlayer and magnetic layer materials, and by controlling the underlayer deposition conditions so that the magnetic layer is epitaxially grown by a growth mechanism which is predominantly layer by layer. In an embodiment of the present invention, an underlayer comprising an alloy of chromium with vanadium, titanium or manganese, or an underlayer comprising a nickel-aluminum alloy, is sputter deposited at a pressure less than about 10 mTorr, substrate temperature greater than about 300.degree. C. and substrate bias greater than about 300 V, and a cobalt magnetic layer is epitaxially grown thereon, predominantly layer by layer.

Abstract: Double layer, or bi-layer, magnetic films are deposited over a substrate with an underlayer. The bi-layer film is a film of two different magnetic layers which have different chemical composition, deposited with no spacer layer between the two layers. The lower magnetic layer should be of a low noise magnetic material, while the upper magnetic layer should be a high coercivity magnetic material. The bi-layer film exhibits a single response to magnetic recording and a joint coercivity different from the coercivity of either layer by itself. A preferred double layer media uses a CoCrTa layer deposited under a CoCrTaPt layer, with the CoCrTa layer comprising 30 to 70% of the total film thickness. The double layer film produces magnetic media with higher coercivity and lower media noise as compared to single layered films of either of the materials of the magnetic layers.

Abstract: A seed layer is deposited under an underlayer in magnetic thin film media. The seed layer material has a similar lattice parameter and a similar crystal structure to the underlayer material. The preferred structure involves a nickel-aluminum seed layer, under a chromium underlayer, under a cobalt-based magnetic layer. Use of the nickel-aluminum seed layer produces higher coercivity and lower media noise in the resultant magnetic thin film. The coercivity and media noise values for the resultant magnetic thin film are dependent upon deposition parameters, and recommended deposition parameters are given.

Abstract: Double layer, or bi-layer, magnetic films are deposited over a substrate with an underlayer. The bi-layer film is a film of two different magnetic layers which have different chemical composition, deposited with no spacer layer between the two layers. The lower magnetic layer should be of a low noise magnetic material, while the upper magnetic layer should be a high coercivity magnetic material. The bi-layer film exhibits a single response to magnetic recording and a joint coercivity different from the coercivity of either layer by itself. A preferred double layer media uses a CoCrTa layer deposited under a CoCrTaPt layer, with the CoCrTa layer comprising 30 to 70% of the total film thickness. The double layer film produces magnetic media with higher coercivity and lower media noise as compared to single layered films of either of the materials of the magnetic layers.