Molecularly linked gamma-Fe2O3 nanoparticles chains arc produced from superparamagnetic gamma-Fe2O3 nanoparticles under zero applied magnetic field. The chains exhibit ferromagnetic interaction between gamma-Fe2O3 nanoparticles that compose them as evidenced by an increase in blocking temperature from similar to 80 K in the case of isolated nanoparticles to similar to 120 K for chains.