  Within the framework of the effective-field theory with correlations we
investigate effects of an external magnetic field and random site dilution on
basic thermodynamic quantities, such as the magnetization and the magnetic
susceptibility, of the geometrically frustrated triangular lattice Ising
antiferromagnet. Behavior of these quantities is presented in the
temperaturefield parameter space for selected mild degrees of dilution. It is
found that, besides the anomalies associated with phase transitions from the
ferrimagnetic to the paramagnetic state, in some regions of the parameter space
these functions display some more anomalies and peculiarities, as a result of
joint effects of the geometrical frustration, magnetic dilution, thermal
fluctuations and the applied magnetic field.
