| CPC G11B 5/607 (2013.01) [G11B 5/4961 (2013.01); G11B 5/581 (2013.01); G11B 5/59638 (2013.01); G11B 21/21 (2013.01); G11B 2005/0021 (2013.01); G11B 5/00821 (2013.01)] | 10 Claims | 

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               1. A magnetic disk device comprising: 
            a magnetic disk; 
                a magnetic head including a write element used to write data to the magnetic disk, a read element used to read data from the magnetic disk, and further including a heater which generates heat by electric power supplied thereto and expands the magnetic head toward the magnetic disk side; and 
                a controller which supplies, at the time of startup of data write, fixed additional electric power for an initial first time of a specified time while supplying steady electric power to the heater for the specified time, and supplies gradually-decreasing additional electric power for a remaining second time of the specified time, the steady electric power being used to make spacing between the magnetic disk and the magnetic head become saturated at a target value. 
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