A doped antimony telluride, its preparation method and use
By carrying out hydrothermal reaction and post-processing steps under alkaline conditions, a doped antimony telluride phase change material with good uniformity was prepared, which solved the problems of poor uniformity and phase separation in existing doped phase change materials and realized simple and low-cost industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIHANG UNIV
- Filing Date
- 2024-03-08
- Publication Date
- 2026-07-14
AI Technical Summary
In existing technologies, doped phase change materials have poor uniformity and uncontrollable element distribution, which easily leads to phase separation, affecting device performance and resulting in high cost and complex process flow, thus limiting the commercial application of phase change memory.
By using antimony source, tellurium source and compound containing doped elements to carry out hydrothermal reaction under alkaline conditions, combined with post-processing steps, a homogeneous doped antimony telluride phase change material was prepared, avoiding phase separation.
This method achieves good uniformity in antimony telluride doping, simplifies the preparation process, reduces costs, makes it suitable for industrial production, and improves the performance stability of phase change materials.
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Figure CN118145605B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of phase change materials technology, specifically relating to a doped antimony telluride, its preparation method, and its application. Background Technology
[0002] Phase-change memory (PCM) is an emerging non-volatile memory technology with advantages such as fast read / write speeds, low power consumption, high density, and long lifespan. Therefore, it has attracted much attention in the field of computer storage and is considered the most promising next-generation semiconductor memory. Despite its many advantages, PCM suffers from problems such as poor amorphous stability and slow crystallization speed, which reduce its storage lifespan and cycle stability, thus limiting its large-scale commercialization.
[0003] Doping phase change materials (PCMs) can effectively improve their crystallization rate and thermal stability. Currently, dual-target co-sputtering is commonly used to obtain doped PCMs. However, PCMs prepared by this method typically exhibit poor uniformity, uncontrollable elemental distribution, and are prone to phase separation, severely impacting device performance. Furthermore, this method is costly and involves complex processes. Therefore, there is an urgent need to find new doping methods. Summary of the Invention
[0004] The purpose of this invention is to provide a doped antimony telluride, its preparation method, and its application. The method provided by this invention is simple, the raw materials are readily available, and the obtained doped antimony telluride has good uniformity and is not prone to phase separation.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] This invention provides a method for preparing doped antimony telluride, comprising the following steps:
[0007] An antimony source, a tellurium source, a compound containing a dopant element, and a solvent are mixed. After adjusting the pH of the resulting mixture to be alkaline, a hydrothermal reaction is carried out to obtain the doped antimony telluride.
[0008] Preferably, the antimony source includes antimony chloride; the tellurium source includes elemental tellurium.
[0009] Preferably, the dopant element in the compound containing the dopant element includes yttrium and / or scandium;
[0010] The doped compound includes doped nitrates or doped sulfates.
[0011] Preferably, the solvent includes anhydrous ethanol and ethylene glycol;
[0012] The volume ratio of anhydrous ethanol to ethylene glycol is 1:1 to 4.
[0013] Preferably, the molar ratio of the dopant element, Sb and Te is x:(4-x):9, based on the amount of substance of the dopant element, Sb and Te, and the value of x is in the range of 0<x≤0.8.
[0014] Preferably, the alkaline pH value is 13 or higher.
[0015] Preferably, the temperature of the hydrothermal reaction is 200-250°C, and the holding time is greater than 24 hours.
[0016] Preferably, after the hydrothermal reaction, the reaction system is further subjected to post-processing, which includes sequentially cooling, separating, washing and drying.
[0017] The cleaning process includes: washing the separated product with ethanol and deionized water until neutral, centrifuging to obtain a precipitate, dispersing the precipitate in deionized water by ultrasonication, and repeating the above cleaning steps.
[0018] The drying method is constant temperature drying, with a drying temperature of 40–80°C, a drying time of more than 8 hours, and a vacuum degree of 1×10⁻⁶. -3 Pa or above.
[0019] The present invention also provides doped antimony telluride prepared by the preparation method described in the above technical solution.
[0020] This invention also provides the application of the doped antimony telluride described in the above technical solution as a phase change material.
[0021] This invention provides a method for preparing doped antimony telluride, comprising the following steps: mixing an antimony source, a tellurium source, a compound containing the dopant element, and a solvent; adjusting the pH of the resulting mixture to alkaline; and then performing a hydrothermal reaction to obtain the doped antimony telluride. The preparation method provided by this invention is simple, uses readily available raw materials, and requires no toxic (e.g., hydrazine hydrate) or highly hazardous (e.g., sodium borohydride) external reducing agents. Utilizing a disproportionation reaction under strongly alkaline conditions, and through an ionic reaction process, a reliable doped antimony telluride phase change material with high quality and purity is synthesized, making it more suitable for industrial production. Attached Figure Description
[0022] Fig. 1 The structural characterization results of the antimony telluride phase change material obtained in Comparative Example 1 are shown, where a is the XRD spectrum of antimony telluride, b is the elemental ratio of antimony telluride, and c and d are the elemental surface distribution diagrams of antimony telluride.
[0023] Fig. 2 The scanning electron microscope images and elemental distribution diagrams of yttrium-doped antimony telluride obtained in Example 1 are shown.
[0024] Fig. 3These are scanning electron microscope images and elemental distribution diagrams of the scandium-doped antimony telluride phase change material powder obtained in Example 3. Detailed Implementation
[0025] This invention provides a method for preparing doped antimony telluride, comprising the following steps:
[0026] An antimony source, a tellurium source, a compound containing a dopant element, and a solvent are mixed. After adjusting the pH of the resulting mixture to be alkaline, a hydrothermal reaction is carried out to obtain the doped antimony telluride.
[0027] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.
[0028] In this invention, the antimony source comprises antimony chloride, which is preferably added in powder form. In this invention, the tellurium source comprises elemental tellurium, which more preferably comprises tellurium powder or tellurium flakes. In this invention, the dopant element in the dopant-containing compound preferably comprises yttrium and / or scandium; the dopant-containing compound comprises a dopant-containing nitrate or a dopant-containing sulfate.
[0029] In this invention, the molar ratio of the dopant element, Sb and Te is preferably x:(4-x):9, based on the amount of substance of the dopant element, Sb and Te, and the value of x is preferably in the range of 0 < x ≤ 0.8.
[0030] In this invention, the solvent preferably comprises anhydrous ethanol and ethylene glycol; the volume ratio of the anhydrous ethanol to ethylene glycol is preferably 1:1 to 4. This invention does not impose any particular limitation on the amount of solvent added, and any solvent well known to those skilled in the art can be used.
[0031] In this invention, the alkaline pH value is preferably 13 or higher, more preferably 13; the reagent used to adjust the pH value of the resulting mixture is preferably sodium hydroxide or potassium hydroxide.
[0032] In this invention, the mixing method is preferably magnetic stirring, and the magnetic stirring time is preferably 1 hour.
[0033] In this invention, the temperature of the hydrothermal reaction is preferably 200–250°C, and the holding time is preferably greater than 24 hours. In this invention, the hydrothermal reaction is preferably carried out in a stainless steel reactor with a polytetrafluoroethylene liner.
[0034] Following the hydrothermal reaction, the present invention preferably includes post-processing of the obtained reaction system, which preferably includes sequential cooling, separation, washing, and drying. In the present invention, the cooling method is preferably furnace cooling to room temperature. In the present invention, the washing preferably includes: washing the separated product with ethanol and deionized water until neutral, centrifuging to obtain a precipitate, dispersing the precipitate in deionized water using ultrasound, and repeating the above washing steps; the alternating washing with ethanol and deionized water is preferably performed at least three times until the pH of the washing solution is neutral. In the present invention, the repetition is preferably performed three times. In the present invention, the drying method is preferably constant temperature drying, the drying temperature is preferably 40–80°C, the drying time is preferably at least 8 hours, and the vacuum degree is preferably 1×10⁻⁶. -3 Pa or above.
[0035] The present invention also provides doped antimony telluride prepared by the preparation method described in the above technical solution.
[0036] This invention also provides the application of the doped antimony telluride described in the above technical solution as a phase change material.
[0037] To further illustrate the present invention, the following detailed description, in conjunction with the accompanying drawings and embodiments, provides a method for preparing and applying a doped antimony telluride, but these descriptions should not be construed as limiting the scope of protection of the present invention.
[0038] Example 1
[0039] Preparation of Y x Sb 2-x Te3, x is 0.15, that is, Y 0.15 Sb 1.85 Te3;
[0040] 0.3 mmol of yttrium nitrate, 3.7 mmol of antimony trichloride and 9 mmol of tellurium powder were dispersed in 80 mL of solvent (40 mL of ethylene glycol and 40 mL of anhydrous ethanol). Then, 0.1 mol of potassium hydroxide was added to adjust the pH of the mixture to 13. The mixture was magnetically stirred for 1 h to obtain a homogeneous reaction precursor mixture.
[0041] The obtained precursor mixture was transferred into a stainless steel reactor with a polytetrafluoroethylene liner. The reactor was heated to 200°C for hydrothermal reaction and held at that temperature for 24 hours. After the reaction was completed, the reactor was cooled to room temperature with the furnace. The reactor was then removed, the upper clear liquid was discarded, and the lower precipitate was obtained.
[0042] The resulting lower precipitate was washed three times alternately with ethanol and deionized water until neutral. Then, it was centrifuged, and the lower precipitate was collected. The precipitate was then dispersed in deionized water using ultrasonic vibration. This process was repeated three times. Finally, the precipitate was dried in a vacuum drying oven at a constant temperature (80℃, 12h, vacuum 1×10⁻⁶). -3 Pa), thus obtaining Y 0.15 Sb 1.85 Te3 material.
[0043] Example 2
[0044] Preparation of Y x Sb 2-x Te3, x = 0.25, i.e., Y 0.25 Sb 1.85 Te3;
[0045] 0.5 mmol of yttrium nitrate, 3.5 mmol of antimony trichloride and 9 mmol of tellurium powder were dispersed in 80 mL of solvent (30 mL of ethylene glycol and 50 mL of anhydrous ethanol). Then, 0.05 mol of potassium hydroxide was added to adjust the pH of the mixture to 13. The mixture was magnetically stirred for 1 h to obtain a homogeneous reaction precursor mixture.
[0046] The obtained precursor mixture was transferred into a stainless steel reactor with a polytetrafluoroethylene liner. The reactor was heated to 250°C for hydrothermal reaction and held at that temperature for 30 hours. After the reaction was completed, the reactor was cooled to room temperature with the furnace. The reactor was then removed, the upper clear liquid was discarded, and the lower precipitate was obtained.
[0047] The resulting lower precipitate was washed three times alternately with ethanol and deionized water until neutral. Then, it was centrifuged to collect the lower precipitate. The precipitate was then dispersed in deionized water using ultrasonic vibration. This process was repeated three times. Finally, the precipitate was dried in a vacuum drying oven at a constant temperature (60℃, 12h, vacuum 1×10⁻⁶). -3 Pa), thus obtaining Y 0.25 Sb 1.85 Te3 material.
[0048] Example 3
[0049] Preparation of Sc x Sb 2-x Te3, x = 0.15, i.e., Sc 0.15 Sb 1.85 Te3;
[0050] 0.3 mmol scandium nitrate, 3.7 mmol antimony trichloride and 9 mmol tellurium powder were dispersed in 80 mL of solvent (30 mL ethylene glycol and 50 mL anhydrous ethanol). Then, 0.05 mol potassium hydroxide was added to adjust the pH of the mixture to 13. The mixture was magnetically stirred for 1 h to obtain a homogeneous reaction precursor mixture.
[0051] The obtained precursor mixture was transferred into a stainless steel reactor with a polytetrafluoroethylene liner. The reactor was heated to 200°C for hydrothermal reaction and held at that temperature for 24 hours. After the reaction was completed, the reactor was cooled to room temperature with the furnace. The reactor was then removed, the upper clear liquid was discarded, and the lower precipitate was obtained.
[0052] The resulting lower precipitate was washed three times alternately with ethanol and deionized water until neutral. Then, it was centrifuged to collect the lower precipitate. The precipitate was then dispersed in deionized water using ultrasonic vibration. This process was repeated three times. Finally, the precipitate was dried in a vacuum drying oven at a constant temperature (80℃, 12h, vacuum 1×10⁻⁶). -3 Pa), thus obtaining Sc 0.15 Sb 1.85 Te3 material.
[0053] Comparative Example 1
[0054] To prepare Sb₂Te₃, i.e., without doping;
[0055] 4 mmol of antimony trichloride and 9 mmol of tellurium powder were dispersed in 80 mL of solvent (40 mL of ethylene glycol and 4 mL of anhydrous ethanol), and then 0.1 mol of potassium hydroxide was added to adjust the pH of the mixture to 13. The mixture was magnetically stirred for 1 h to obtain a homogeneous reaction precursor mixture.
[0056] The obtained precursor mixture was transferred into a stainless steel reactor with a polytetrafluoroethylene liner. The reactor was heated to 200°C for hydrothermal reaction and held at that temperature for 24 hours. After the reaction was completed, the reactor was cooled to room temperature with the furnace. The reactor was then removed, the upper clear liquid was discarded, and the lower precipitate was obtained.
[0057] The resulting lower precipitate was washed three times alternately with ethanol and deionized water until neutral. Then, it was centrifuged to collect the lower precipitate. The precipitate was then dispersed in deionized water using ultrasonic vibration. This process was repeated three times. Finally, the precipitate was dried in a vacuum drying oven at a constant temperature (60℃, 12h, vacuum 1×10⁻⁶). -3 Pa), thus obtaining Sb2Te3 material.
[0058] Performance testing
[0059] Test Example 1
[0060] Fig. 1 The structural characterization results of the antimony telluride phase change material obtained in Comparative Example 1 are shown, where a is the XRD spectrum of antimony telluride, b is the elemental ratio of antimony telluride, and c and d are the elemental surface distribution diagrams of antimony telluride. Fig. 2 The scanning electron microscope images and elemental distribution diagrams of yttrium-doped antimony telluride obtained in Example 1 are shown.
[0061] Fig. 3 These are scanning electron microscope images and elemental distribution diagrams of the scandium-doped antimony telluride phase change material powder obtained in Example 3;
[0062] from Figs. 1-3 As can be seen, the dopant elements are uniformly distributed in the antimony telluride phase change material, and the product exhibits a regular hexagonal nanosheet morphology. XRD characterization also confirms that its crystal structure is consistent with that of the standard material. Therefore, the preparation method provided by this invention can efficiently synthesize antimony telluride phase change materials that meet the expected stoichiometric ratio. Moreover, the preparation method is simple, the raw materials are readily available, safe, and non-toxic, making it more suitable for industrial production.
[0063] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. A method for preparing doped antimony telluride, characterized in that, The steps are as follows: An antimony source, a tellurium source, a compound containing a dopant element, and a solvent are mixed. After adjusting the pH of the resulting mixture to alkaline, a hydrothermal reaction is carried out to obtain the doped antimony telluride. The antimony source includes antimony chloride; the tellurium source includes elemental tellurium; the dopant element in the compound containing the dopant element includes yttrium and / or scandium; the compound containing the dopant element includes a nitrate containing the dopant element or a sulfate containing the dopant element. The solvent is anhydrous ethanol and ethylene glycol; the volume ratio of anhydrous ethanol to ethylene glycol is 1:1~4; The alkaline pH value is 13; The hydrothermal reaction is carried out at a temperature of 200~250℃ and the holding time is greater than 24h.
2. The preparation method according to claim 1, characterized in that, The molar ratio of the dopant element, Sb, and Te is x:(4-x):9, based on the amount of substance of the dopant element, Sb, and Te, and the value of x is in the range of 0 < x ≤ 0.
8.
3. The preparation method according to claim 1, characterized in that, The hydrothermal reaction is followed by post-processing of the resulting reaction system, which includes sequential cooling, separation, washing and drying. The cleaning process includes: washing the separated product with ethanol and deionized water until neutral, centrifuging to obtain a precipitate, dispersing the precipitate in deionized water by ultrasonication, and repeating the above cleaning steps. The drying method is constant temperature drying, with a drying temperature of 40~80℃, a drying time of more than 8 hours, and a vacuum degree of 1×10⁻⁶. -3 Pa or above.
4. The doped antimony telluride prepared by the preparation method according to any one of claims 1 to 3.
5. The application of the doped antimony telluride as described in claim 4 as a phase change material.