The thermodynamical properties of toroidal black holes in the grand canonic
al ensemble are investigated using York's formalism. The black hole is encl
osed in a cavity with finite radius where the temperature and electrostatic
potential are fixed. The boundary conditions allow one to compute the rele
vant thermodynamical quantities, e.g., thermal energy, entropy, and specifi
c heat. This black hole is thermodynamically stable and dominates the grand
partition function. This means that there is no phase transition, such as
the one encountered for spherical black holes. (C) 2000 American Institute
of Physics. [S0022-2488(00)05805-9].