Mn 1-x Zn x Fe 2 O 4 thin films with various Zn contents and of different thickness were synthesized on glass substrates directly by electroless plating in aqueous solution at 90 without heat treatment. The Mn℃ -Zn ferrite films have a single spinel phase structure and well-crystallized columnar grains growing perpendicularly to the substrates. The results of conversion electron 57 Fe Mössbauer spectroscopy (CEMS) indicate that the cation distribution of Mn 1-x Zn x Fe 2 O 4 ferrite nanocrystal thin films fabricated by electroless plating is different from the bulk materials' and a great quantity of Fe 3+ ions are still present on A sites for x>0.5. When the Zn content of the films increases, Fe 3+ ions in the films transfer from A sites to B sites and the hyperfine magnetic field reduces, suggesting that Zn 2+ has strong chemical affinity towards the A sites. On the other side, with the increase of the thickness of the films, Fe 3+ ions, at B sites in the spinel structure, increase and the array of magnetic moments no longer lies in the thin film plane completely. At x = 0.5, H c and M s of Mn 1-x Zn x Fe 2 O 4 thin films show a minimum of 3.7 kA/m and a maximum of 419.6 kA/m, respectively.
Mn-Zn ferrite, thin films, CEMS, electroless platingIn recent years, as electronic devices have become more miniaturized, offering increasing high levels of performance, the study of electronic devices under much higher-signal frequencies has become a trend. Metal alloy, as a potential candidate, has limited applications because of their high conductivity and serious eddy currency loss at high frequencies. On the contrary, owing to their large resistivities, low power losses, and high permeabilities, ferrites have become very important in high frequency soft magnetic applications. Soft magnetical Mn-Zn or Ni-Zn ferrite thin films with high resistivity and ac permeability were pioneering in applications pertinent to micro-inductors and micro-transformers [1][2][3] . Thus many groups put their emphasis on studying magnetic properties and microstructure of Mn-Zn ferrite thin films recently [4][5][6][7] .Although Mn-Zn ferrite films have such good properties including high resistivity, good quality at high frequency, and good performance of soft magnetis, during their preparation there are many factors that are not easy to control. Mn-Zn ferrite is sensitive to its fabrication environment, especially at high annealing temperature. About 20 years ago [8][9][10] , Abe and his co-workers introduced a low-temperature (T<100 ) electroless plating ℃ technique in aqueous solution to prepare magnetic spinel thin films of high crystalline quality without direct heat treatment. They have also conducted a detailed and further research pertinent to technique mechanism as well as have been improving the technique constantly. Based on these improvements, spraying and the spin coating