The entropy of a Kim black hole and the nernst theorem

We start with Klein-Gordon equation on the background of the Kim black hole and calculate the free energy and entropy of a scalar field by the brick-w all method. It is shown that the entropy is not only related to the area of an outer horizon but also is a function of inner horizon's area. Taking so me approximation, we can obtain that the entropy only is proportional to th e area of an outer horizon. Further more, the entropy expressed by location parameter of the outer and inner horizon approaches zero, when the radiati on temperature of a black hole approaches zero. This satisfies the Nernst t heorem. It can be taken as Planck absolute entropy of a black hole.