Magnetic recording medium based on multiferroic film and write-in method thereof

Abstract

The invention relates to a magnetic recording medium based on a multiferroic film, comprising a substrate and a medium layer growing on the substrate. The medium is characterized in that the medium layer comprises a ferroelectric structure unit formed by a ferroelectric material and a ferromagnetic structure unit formed by a ferromagnetic material. The write-in method comprises the following steps: an electric signal generated by a signal source is applied to two ends of the ferroelectric structure unit; an impulse voltage signal generated by the signal source changes the polarized state of a ferroelectric layer; through a magnetoelectric coupling effect, changes of the polarized state can further change the magnetization direction in the ferroelectric structure unit so as to record the state of an electric signal and complete information storage. Compared with the prior art, the invention provides the novel magnetic recording medium of the multiferroic composite material and several structures for recording the medium based on the traditional magnetic recording medium; and the medium using the multiferroic materials for recording can realize the magnetic recording method for electric write-in, and has wide application prospect for novel multifunctional devices with high density storage.

Description

technical field [0001] The invention relates to a magnetic recording medium and a writing method thereof, in particular to a magnetic recording medium based on a multiferroic composite thin film and a magnetic recording method using electric writing. Background technique [0002] With the continuous development of society, the exchange of information has become more and more important, and the exponential growth of information has higher and higher requirements for information storage. Magnetic recording technology was born in 1898. As a traditional information recording technology, magnetic recording technology continues to accept the challenge of high-capacity information storage, and has continuously made leapfrog progress in recording media and read heads. Magnetic recording technology occupies a pivotal position in the field of information storage by virtue of the advantages of high storage density, large storage capacity, high speed and low price. [0003] Magnetic re...

AI Technical Summary

Problems solved by technology

In order to generate a sufficiently strong write magnetic signal, a certain number of coils are required, and there is inevitably a stray magnetic field in the write head, which makes it difficult to reduce the size of the write head, but with the increase of the magnetic recording density ( For example, in 1996 the magnetic recording density was 1Gbit / in 2 , now can reach 400Gb / in 2 ), requiring smaller size and higher sensitivity for the writing head and reading head, which poses new challenges to the writing method, and it is an inevitable trend to study the method of directly writing electrical signals into magnetic recording media

The traditional magnetic recording method is horizontal magnetic recording, that is, the magnetic domains are magnetized in the plane. Similarly, with the development of high-density storage, horizontal magnetic recording has encountered serious obstacles, because under high-density storage, horizontal magnetic recording is It is unstable, but perpendicular magnetic recording is stable under high-density storage, which makes horizontal magnetic recording gradually replaced by perpendicular magnetic recording. Correspondingly, perpendicular magnetic recording media have been greatly developed (such as Co-Cr based Alloy, Co-Cr base-oxide material, L10 phase FePt, Co / Pt multilayer film and ferrite material), however, the perpendicular magnetic recording medium currently studied is still related to magnetic signal writing, and the development and The magnetic recording medium associated with electrowriting is complementary to the method of electrowriting

The read method and the physical effect are closely related. The traditional magnetic read head is based on the anisotropic magnetoresistance (AMR) effect, but the magnetoresistance change produced by the AMR effect is about 1-2%, which makes the magnetic recording Density is difficult to break through 5Gb / in 2 In 1988, the discovery of the giant magnetoresistance effect (GMR) broke this bottleneck, because the GMR effect can produce 100% magnetoresistance change, which makes the GMR read head meet the requirements of high-density storage, with the GMR read head development, and other new types of read heads (such as giant magnetoresistance spin valve read heads, giant magnetoresistance tunnel valve read heads), which are indispensable for high-density storage

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