CN103074680B - Preparation method for hafnium two-dimensional atomic crystal material - Google Patents

Abstract

The invention discloses a preparation method of a hafnium two-dimensional atomic crystal material. The preparation method of the hafnium two-dimensional atomic crystal material comprises: 1) evaporation and deposition of an appropriate amount of hafnium on a transition metal iridium substrate in a vacuum environment; The sample is annealed to make the hafnium atoms interact to form a two-dimensional long-range ordered film structure on the surface of the substrate, in which the hafnium atoms are periodically arranged in a hexagonal honeycomb shape to form a new type of two-dimensional atomic crystal material. This new material with a graphene-like structure expands the research field of non-carbon-based two-dimensional honeycomb crystal materials, and has high scientific research value and potential application potential.

Description

A kind of preparation method of hafnium two-dimensional atomic crystal material

technical field

The invention relates to a preparation method of a hafnium two-dimensional atomic crystal material, which belongs to the technical field of nanometer materials.

Background technique

Two-dimensional atomic crystal materials have become a research hotspot in the world's scientific and technological circles in recent years because of their single-atom-thick planar crystal structure, rich and unique physical and chemical properties, and potential huge application value. Among them, graphene has become the focus and representative of new two-dimensional atomic crystal materials since it was successfully exfoliated in 2004.

Graphene exhibits a series of peculiar electronic and physical properties, such as high mobility, high mechanical strength, high light transmittance, high conductivity, etc., in the fields of microelectronics, micro-nano devices, transparent conductive films, and high-efficiency conversion batteries. It has important application prospects. The upsurge in graphene research has stimulated people's enthusiasm for exploration and research on other new two-dimensional atomic crystal materials (non-carbon-based, graphene-like structures).

For example, silicene, as the silicon-based counterpart of graphene, has been theoretically predicted the possibility of its existence and excellent properties similar to graphene. Other two-dimensional crystal materials with graphene-like structures, such as boron nitride and molybdenum disulfide, have shown many excellent physical properties.

When today's microelectronics is facing the limit of physical size, the development and application of these new two-dimensional planar materials represented by graphene are expected to integrate the current microelectronic silicon-based technology and break through the bottleneck problem encountered by large-scale integrated circuits. my country's basic science, information science, material science, energy science and other research fields provide new opportunities and platforms, which will have a significant and far-reaching impact on the sustainable development of the national economy and the strengthening of national defense security.

Contents of the invention

In view of this, the object of the present invention is to provide a hafnium two-dimensional atomic crystal material and a preparation method thereof, which can grow a novel two-dimensional atomic crystal material, which is two-dimensionally ordered and hafnium atoms are hexagonal A two-dimensional periodic structure in a honeycomb arrangement.

The invention provides a hafnium two-dimensional atomic crystal material, in which the hafnium atoms are arranged in a hexagonal honeycomb shape and periodically expand in a two-dimensional plane.

The invention provides a method for preparing a hafnium two-dimensional atomic crystal material, the steps comprising:

1) In a vacuum environment, an appropriate amount of metal hafnium is evaporated and deposited on the transition metal substrate;

2) Annealing the whole sample, so that the hafnium covering the surface of the substrate interacts to form a two-dimensional ordered periodic structure with hexagonal honeycomb distribution.

The hafnium used above is deposited on the transition metal substrate by electron beam evaporation.

The above-mentioned transition metal substrate for growing the two-dimensional atomic crystal material of hafnium is the (111) plane of iridium.

The above-mentioned annealing temperature for growing the hafnium two-dimensional atomic crystal material is 350°C-450°C, preferably 400°C.

The hafnium two-dimensional atomic crystal material forms a honeycomb structure with a period of 0.54 nm, and the periodic structure can be characterized by a scanning tunneling microscope and a low-energy electron diffractometer.

The invention grows a high-quality hafnium two-dimensional atomic crystal material by an epitaxy method. The hafnium atoms are arranged in a hexagonal honeycomb shape and expand in a two-dimensional plane, which is convenient for further research on the electronic properties of the hafnium two-dimensional atomic crystal material and the development of related devices. This two-dimensional crystal material is different from graphene. The performance of graphene is determined by sp orbital hybrid electrons; while hafnium is a transition metal, the performance of this hafnium two-dimensional atomic crystal material is mainly determined by d orbitals. Electronics determine that d-orbital electrons can induce novel properties such as spin, so this new type of two-dimensional atomic crystal material can be applied to spintronics and device research.

Description of drawings

Below, describe embodiment of the present invention in detail in conjunction with accompanying drawing, wherein:

Fig. 1 shows the schematic diagram of the effect of the overall preparation process of the present invention;

Fig. 2 shows the scanning tunneling microscope image of the high-coverage hafnium particles deposited on the (111) surface of iridium in the present invention;

Fig. 3 shows the scanning tunneling microscope image of the high-quality hafnium two-dimensional atomic crystal material prepared on the (111) face of iridium in the present invention;

Figure 4 shows the low-energy electron diffraction pattern of the hafnium two-dimensional atomic crystal material prepared after the sample is annealed at 400°C in the present invention, including the diffraction spots of the (2x2) superstructure in the base iridium and hafnium two-dimensional atomic crystal material;

Fig. 5 shows the enlarged scanning tunneling microscope image and the corresponding atomic structure model of the high-quality hafnium two-dimensional atomic crystal material prepared on the (111) surface of iridium in the present invention.

Detailed ways

The preparation method of the hafnium two-dimensional atomic crystal material will be further described in detail below with reference to the drawings and examples. This embodiment is only used to illustrate the invention in more detail, and should not be used to limit the invention in any form.

In this embodiment, a high-quality hafnium two-dimensional atomic crystal material is prepared on the surface of a transition metal. The specific steps are as follows: firstly, the iridium single crystal is sputtered with argon ions more than a dozen times in a vacuum chamber, and then the iridium substrate is heated and kept at 850°C for high-temperature annealing to obtain a clean and smooth (111) crystal plane. The schematic diagram of the effect of the overall preparation process of the present invention is shown in FIG. 1 . The upper part of the figure shows the hafnium particles with high coverage deposited on the (111) surface of iridium in the present invention; dimensional atomic crystal material.

Afterwards, on the clean and flat iridium surface, metal hafnium is evenly deposited on it by electron beam evaporation source, and the substrate is kept at room temperature. Hafnium is randomly distributed on the substrate surface, as shown in the scanning tunneling microscope image in Figure 2.

The sample deposited with hafnium particles was annealed at 400°C, the hafnium particles deposited on the substrate surface disappeared, as shown in Figure 3, and a structure with a period of 0.54nm was formed on the iridium surface, which originated from A two-dimensional ordered hafnium atomic crystal material formed on the surface of the sample after annealing treatment. The low-energy electron diffraction pattern of Figure 4 indicates the existence of this ordered structure. This structure with a period of 0.54nm corresponds to a two-dimensional ordered hafnium atom crystal material formed after hafnium atoms are arranged in a hexagonal honeycomb shape on the substrate surface, as shown in FIG. 5 .

Although the present invention has been described in detail above, various conditions can be appropriately changed without departing from the main idea of the present invention. It is to be understood that the present invention is not limited to the embodiments described above, but falls within the scope of the claims, which include equivalents to each of the elements described. For example, metal hafnium can be deposited on the substrate by other methods than electron beam evaporation, such as direct heating of hafnium rods, and effects comparable to those of the above-mentioned embodiments can also be achieved.

Claims (4)

1. a preparation method for hafnium two-dimensional atomic crystal material, is characterized in that, comprises as follows

Step:

1) under vacuum conditions, by the hydatogenesis of appropriate metallic substance hafnium in transition metal base; For growing (111) face that the transition metal substrate of hafnium two-dimensional atomic crystal material is iridium;

2) anneal is carried out to whole sample, interact to make the hafnium atom covering substrate surface produce, form the periodic structure of the sequential 2 D of hexagon cellular shape arrangement, thus obtain hafnium two-dimensional atomic crystal material.

2. the method for claim 1, is characterized in that, hafnium used is deposited in transition metal substrate by the method for electron beam evaporation.

3. the method for claim 1, is characterized in that, the annealing temperature of carrying out hafnium two-dimensional atomic crystal Material growth is 350 DEG C ~ 450 DEG C.

4. the method for claim 1, it is characterized in that, described hafnium two dimensional crystal material, hafnium atom defines the ordered structure of hexagon cellular shape arrangement, cell pitch is 0.54nm, this periodic structure can by scanning tunnel microscope and low electron energy diffractometer characterize.