An in situ preparation of superparamagnetic Fe by atomic layer deposition 3 o 4 nanotube array method

Abstract

The invention discloses a method for in-situ preparing super-paramagnetic Fe3O4 nanotube arrays by atomic layer deposition, and belongs to the technical field of preparation of nanotube arrays. The method comprises the following steps: 1) conveying a clean AAO (Anodic Aluminum Oxide) substrate into an atomic layer deposition device for later use; 2) charging ferrocene steam and oxygen into a gas carrying system of the atomic layer deposition device, conveying into a vacuum reaction cavity through the gas carrying system, starting atomic layer deposition circulation under the nitrogen atmosphere, and repeating the circulation until uniform Fe3O4 films are generated on the surface and holes of the AAO substrate; 3) polishing to remove the Fe3O4 film on the surface of the AAO substrate; 4) dissolving to remove the AAO substrate through aqueous alkali to obtain orderly-arranged Fe3O4 nanotube arrays. The method is simple to operate, wide in raw material source, and easy to be achieved; the super-paramagnetic Fe3O4 nanotube arrays which are very large in aspect ratio, are orderly arranged and are very uniform in shape and size can be obtained by in-situ growth.

Description

technical field [0001] The invention belongs to the technical field of preparation of nanotube arrays, in particular to an in-situ preparation of superparamagnetic Fe by atomic layer deposition 3 o 4 Methods for nanotube arrays. Background technique [0002] Spintronics and biomedicine have driven the rapid growth of high-quality superparamagnetic nanostructures, leading to the rapid development of precise and controllable growth of superparamagnetic nanostructures, such as magnetic resonance imaging, drug delivery and cancer therapy. However, to date, the preparation of Fe 3 o 4 The methods of nanotubes mainly include the following: (1) The composite fiber precursor nanowires are prepared by electrospinning, and then the precursor nanowires are sintered and reduced at high temperature to prepare Fe 3 o 4 nanotubes, the process of this method is cumbersome and complicated, and the preparation process requires high-temperature sintering and reduction. The prepared Fe 3 ...

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Problems solved by technology

However, to date, the preparation of Fe 3 o 4 The methods of nanotubes mainly include the following: (1) The composite fiber precursor nanowires are prepared by electrospinning, and then the precursor nanowires are sintered and reduced at high temperature to prepare Fe 3 o 4 nanotubes, the process of this method is cumbersome and complicated, and the preparation process requires high-temperature sintering and reduction. The prepared Fe 3 o 4 The nanotubes are randomly oriented ferromagnetic phase nanotube networks instead of superparamagnetic Fe 3 o 4 nanotube array

(2) Preparation of Fe by reduction method 3 o 4 Nanotubes, this method is to prepare α-Fe by hydrothermal method 2 o 3 nanotubes, then α-Fe 2 o 3 Nanotubes were annealed at high temperature under a reducing atmosphere to obtain Fe 3 o 4 Nanotubes, Fe obtained by this method 3 o 4 Nanotubes are also randomly oriented ferromagnetic phases, and it is impossible to obtain well-arranged superparamagnetic Fe 3 o 4 nanotube array

(3) Preparation of Fe by template method 3 o 4 Nanotube arrays, which utilize sol-gel method and AAO templates to prepare α-Fe 2 o 3 Nanotube array, and then by the α-Fe obtained in the previous step 2 o 3 Subsequent reduction annealing of nanotube arrays to prepare Fe 3 o 4 Nanotube arrays, although this method can obtain neatly arranged Fe 3 o 4 nanotube arrays, but due to the need for high-temperature sintering in air and high-temperature annealing in reducing atmosphere during the preparation process, the prepared Fe 3 o 4 The nanotube arrays are all in the ferromagnetic phase

However, the preparation of magnetic nanostructures by ALD is still a very challenging task, because the preparation process of magnetic nanostructures involves complex binary or ternary chemical reactions and the control of magnetic evolution.

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