Study of NiCuZn ferrite powders and films prepared by sol—gel method

Abstract

This paper reports that a series of NiCuZn ferrite powders and films are prepared by using sol—gel method. The effects of raw material composition and the calcinate temperature on magnetic properties of them are investigated. The NiCuZn ferrite powders are prepared by the self-propagating high-temperature synthesis method and subsequently heated at 700 °C∼1000 °C. The results show that NiCuZn ferrite powders with single spinel phase can be formed after heat-treating at 750 °C. Powders obtained from Ni0.4Cu0.2Zn0.4Fe1.9O4 gel have better magnetic properties than those from gels with other composition. After heat-treating at 900 °C for 3 h, coercivity Hc and saturation magnetization Ms are 9.7 Oe (1 Oe = 80 A/m) and 72.4 emu/g, respectively. Different from the powders, NiCuZn films produced on Si (100) from the Ni0.4Cu0.2Zn0.4Fe2O4 gel formed at room temperature possess high properties. When heat-treating condition is around 600 °C for 6 min, samples with low Hc and high Ms will be obtained. The minimal Hc is 16.7 Oe and Ms is about 300 emu/cm3. In comparison with the films prepared through long-time heat treating, the films prepared through short heat-treating time exhibits better soft magnetic properties.

The structural and magnetic properties of barium ferrite powders prepared by the sol—gel method

“…[1] The first and most analyzed compound in the BaO-FeO-Fe 2 O 3 ternary system is the so-called M-phase BaFe 12 O 19 , which has a magnetoplumbite structure. [2] Nowadays, barium ferrites are widely used in lowtemperature co-fired ceramics (LTCC) applications because of their stable magnetic performance, high resistivity and anisotropy. [3] The electromagnetic properties of nanoferrites are very sensitive to many factors, including the method of preparation, sintering rate, sintering temperature, sintering duration and sintered additives.…”

Enhanced structural and magnetic properties of microwave sintered Li–Ni–Co ferrites prepared by sol–gel method

“…[3,4] The solgel method is a simple, easy, and less time consuming method for synthesizing homogenous ultrafine ferrite powder with good stoichiometry at low temperature; however, there are also problems such as high cost, environmental pollution by nitrate decomposition, and inconvenient mass production. [5][6][7][8][9] And heat treatment of such fine powders by microwave process is expected to yield ferrites of better quality. Microwave sintering has various advantages like rapid and uniform heating, high reaction rate, reduced sintering temperature, thereby, energy and time saving and thus eco-friendly.…”