Effects of La³⁺ doping on MnZn ferrite nanoscale particles synthesized by hydrothermal method

Abstract

MnZn ferrite nanoscale particles were synthesized by hydrothermal method. The effects of amount of addition La³⁺ on the products were discussed. The product was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The results show that the sample with 0.2% La³⁺ (mass fraction) or without La³⁺ has only spinel phase, but the sample with mass fraction of La³⁺ exceeding 0.4% posses second phase besides the spinel one; and the nano-MnZn ferrites change from cube to hexagon when the mass fractions of La³⁺ is up to 1.2%. TEM image of the sample with 1.2% La³⁺ indicates that the homogeneous hexagonal crystal is obtained and the particles are larger than those of undoped; the addition of La³⁺ has great influence on the crystallization of hydrothermal process and can change the shape of particles and improve their growth. The saturation magnetization of the sample with 1.2% La³⁺ (2.64 A · m² · kg⁻¹) is lower than that of undoped (17.54 A · m² · kg⁻¹) and it behaves superparamagnetically.

Keywords

hydrothermal method / MnZn ferrite / nanoscale particle / doping

References

[1] ZengerM. Modern ferrite technologies and products [J]. Journal of Materials and Product Technology, 1994, 9(4–6): 265-280

[2] TopferJ, SchopsW, NauberP, et al.. Modern developmental trend in the production and application of hard and soft magnetic ferrite materials [J]. CFI Ceram Forum Int, 1999, 76(9): 49-55

[3] LiuC S, WuJ M, TsayM J, et al.. Optimum power-loss and microstructure of MnZn ferrites under consideration of particle size [J]. IEEE Transactions on Magnetics, 1996, 32(5): 4 860-4 862

[4] JeongGeun-Min, ChoiJaeho, KimSung-Soo. Abnormal grain growth and magnetic loss in Mn-Zn ferrites containing CaO and SiO₂ [J]. IEEE Transactions on Magnetics, 2000, 36(5): 3 405-3 407

[5] Gasiorek S, Kulikowski J. Some physical and technological effects of V₂O₅ or Bi₂O₃ on the properties of Ni-Zn ferrites [J]. Journal of magnetism and Magnetic Materials, 1982(26): 295 – 296.

[6] SaleF R, FanJ, ChienY T. The effects of V₂O₅ on the microstructure and magnetic properties of gel-derived Mg-Mn-Zn and Mn-Zn ferrites [J]. Am Ceram Trans, 1995, 47: 155-167

[7] Kwang P C, Won K K, Sung H L, et al. Crystalloraphic and magnetic properties of Ti_xCo_1+xFe_2−2xO₄ ferrite powder [J]. Journal of magnetism and Magnetic Materials, 2001(232): 133–138.

[8] RezlescuE, RezlescuN, PasnicuC, et al.. Nickel-zinc ferrites with Ti-Ge substitution for high-frequency use [J]. Ceramic Int, 1993, 19: 71-75

[9] ZnidarsicA, LimpelM, DrofenikM. Effect of dopants on the magnetic properties of MnZn-ferrites for high frequency power supplies [J]. IEEE Transactions on Magnetics, 1995, 31(2): 950-953

[10] GuYing-ying, SangShang-bin, HuangKe-long, et al.. Synthesis of MnZn ferrite nanoscale particles by hydrothermal method [J]. Journal of Central South University of Technology, 2000, 7(1): 37-39

[11] ChenYa-jie, LiuPei-sheng, JinZong-ming. Studies of La₂O₃ additive in Ni-Zn ferrite [J]. Journal of Materials Science Letters, 1995, 14: 998-1 001

[12] SattarA A, SamyA M, El-ezzaR S, et al.. Effect of rare earth substitution on magnetic and electrical properties of Mn-Zn ferrites [J]. Phys Stat Sol, 2002, 193(1): 86-93

[13] Woo Chul Kim, Seung Wha Lee, Sam Jinkim, et al. Magnetic properties of Y-,La-,Nd-,Gd- and Bi-doped ultrafine CoFe₂O₄ spinel grown by using a sol-gel method [J]. Journal of magnetism and Magnetic materials, 2000(215–216): 217–220.

[14] DuYou-weiFerrites [M], 1996, Nanjing, Science and Technology Publishing Company: 47-47(in Chinese)

[15] ChenXing, DengZhao-xiang, LiYu-peng, et al.. Hydrothermal synthesis and superparamagnetic behaviors of a series of ferrite nano-particles [J]. Chinese Journal of Inorganic Chemistry, 2002, 18(5): 460-464