Zn0.2Mn0.81Zr0.01Fe1.98O4 and Zn0.2Mn0.83Zr0.03Fe1.94O4 thin films with different concentrations of Mn and Zr have been deposited on single crystal n-Si (400) at room temperature (RT) by pulse laser deposition technique (PLD). The films have been deposited under two conditions: (i) with the applied external magnetic field across the propagation of the plume (ii) without applied external magnetic field (B=0). XRD results show the films have spinel cubic structure when deposited in the presence of magnetic field. SEM and AFM observations clearly show the effect of external applied magnetic field on the growth of films in terms of small particle size, improved uniformity and lower r.m.s. roughness. Thin films deposited under the influence of external magnetic field exhibit higher magnetization as measured by the VSM. The optical band gap energy E-g, refractive index n, reflection, absorption and the thickness of the thin films were measured by spectroscopy ellipsometer. The reflection of Zn0.2Mn0.83Zr0.03Fe1.94O4 thin films is higher than Zn0.2Mn0.81Zr0.01Fe1.98O4 thin films due to the greater concentration of Zr. The thicknesses of the thin films under the influence of external magnetic field are larger than the films grown without field for both samples. The optical band gap energy Eg decreases with increasing film thickness. The films with external magnetic field are found highly absorbing in nature due to the larger film thickness. (C) 2011 Elsevier B.V. All rights reserved.