One-dimensional permanent magnetic nano-material, in which hard magnetic tubes are coated with soft magnetic wires and preparation method thereof

Abstract

The invention provides a one-dimensional permanent magnetic nano-material, in which hard magnetic tubes are coated with soft magnetic wires and a preparation method thereof. The material has a composite structure that hard magnetic nano-tubes prepared from hard magnetic phase FePt or CoPt alloy are coated with soft magnetic nano-wires prepared from soft magnetic phase pure metals including Fe, Co and Ni or binary and ternary alloy, wherein, the diameter of the one-dimensional permanent magnetic nano-material is 10nm to 220nm; the diameter of the soft magnetic phase nano-wires is 4nm to 60nm; and the wall thickness of the hard magnetic phase nano-tubes is 3nm to 80nm. The preparation method of the material comprises the following steps: firstly, preparing the hard magnetic alloy nano-tubes in a porous anodic alumina template by using the template wetting method; and then, growing the soft magnetic nano-wires in the nano-tubes by using the electrochemical deposition method. The invention has the advantages that the size of the one-dimensional permanent magnetic nano-material is controllable and the preparation method is simple.

Description

technical field [0001] The invention belongs to the technical field of nanomaterial preparation, and in particular provides a hard magnetic tube-coated soft magnetic linear one-dimensional nano permanent magnet material and a preparation method thereof, which is suitable for hard magnetic tube coated soft magnetic linear one-dimensional nano permanent magnets. Preparation of magnetic materials. Background technique [0002] One of the main uses of soft and hard magnetic coupling is to manufacture high-performance permanent magnetic materials. In 1991, E.F.Kneller et al. proposed a new principle for preparing permanent magnetic materials. When nanoscale soft magnetic materials and hard magnetic materials form composite materials, It will produce exchange coupling effect, promote the appearance of remanence enhancement effect, and produce high magnetic energy product. This nano-exchange-coupled permanent magnet is considered to be an important way to develop the fourth-genera...

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Problems solved by technology

However, the maximum magnetic energy product of the nano-exchange-coupled permanent magnets obtained in the experiment is much lower than the theoretical expectation. Therefore, the development of new preparation technologies and the preparation of nano-exchange-coupled materials by artificial synthesis are the key to increasing the maximum magnetic energy product.

The artificial composite structure currently prepared is mainly to prepare hard / soft magnetic double-layer or multi-layer films by sputtering or epitaxy, including NdFeB / Fe, SmCo / Fe, FePt / Fe, etc. The required equipment is usually relatively expensive, and The prepared material is only nanometer in one dimension, which is not conducive to the miniaturization requirements of future devices. The current trend of device miniaturization also puts forward higher requirements for permanent magnet materials to move towards smaller scales.

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