Large-size copper-doped manganese thiophosphate monocrystal and method for preparing same

Abstract

This invention relates to a large-size copper-doped manganese thiophosphate single crystal and its preparation method, wherein the single crystal has the chemical formula Cu. x Mn y P2S6, where 0

Description

Technical Field

[0001] This invention belongs to the field of crystal material preparation technology, and specifically relates to a large-size copper-doped manganese thiophosphate single crystal and its preparation method. Background Technology

[0002] With the rapid development of information technology, electronic devices are facing higher demands for functional density, energy efficiency, and integration methods. Traditional electronic systems based on electron charge control are gradually showing limitations in low-power operation and multifunctional synergy, necessitating the introduction of new physical mechanisms and material systems. Multiferroic materials, due to the coexistence of multiple order parameters such as ferroelectricity and magnetism within the same system and the potential for significant magnetoelectric coupling effects, provide an ideal platform for achieving synergistic control of multiple degrees of freedom, including electrical and magnetic properties. In recent years, with the continuous development of material design and control methods, multiferroic materials have shown broad application prospects in low-power electronic devices, non-volatile memory, spintronics, and multifunctional integrated devices, becoming an important research direction in condensed matter physics and materials science.

[0003] Obtaining high-quality, large-size single crystals depends on the precise control of mass transport processes and a stable crystal growth environment. For multi-component layered compounds like copper-doped manganese thiophosphate, the numerous constituent elements and stoichiometric relationships make them susceptible to diffusion kinetics and phase equilibrium conditions during growth. Traditional single-crystal preparation methods, such as solution methods, high-temperature solid-state methods, and hydrothermal methods, typically rely on localized reactions or dissolution-recrystallization processes, making it difficult to achieve uniform mass transport over long distances. This results in a large number of crystal nuclei, limited single-crystal growth space, and ultimately smaller crystal sizes with unstable quality. Furthermore, existing processes often require pretreatment operations such as grinding and melting of raw materials, which not only complicates the process but also easily introduces impurities or disrupts the original composition, further affecting the structural integrity and compositional uniformity of the crystal.

[0004] Therefore, there is an urgent need to develop a crystal growth method that enables controlled transport of matter in a closed and clean environment and facilitates preferential nucleation and continuous growth of single crystals, in order to prepare high-quality, large-size copper-doped manganese thiophosphate single crystals, thereby meeting their needs in basic physical property research and related device applications. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a large-size copper-doped manganese thiophosphate single crystal and its preparation method. It has stable chemical properties, and magnetic studies have shown that the material has antiferromagnetism at low temperature and ferroelectricity at room temperature. Therefore, it has application potential in the fields of spintronics and memory devices.

[0006] This invention provides a large-size copper-doped manganese thiophosphate single crystal, the chemical formula of which is Cu. xMn y P2S6, where 0 < x < 2, 0 < y < 2; the space group of the single crystal is C2 / m, and the size is 4 - 12 mm.

[0007] The present invention provides a method for preparing a large-sized copper-doped manganese thiophosphate single crystal, which includes the following steps:

[0008] (1) Weigh Cu powder, Mn block, P block and S powder and place them in a first reaction vessel to obtain a mixture.

[0009] (2) Vacuum-seal the first reaction vessel and place it in a two-zone tube furnace. The bottom of the first reaction vessel is located in the high-temperature zone to make the mixture react, and the top of the first reaction vessel is located in the low-temperature zone for heat preservation to grow a precursor.

[0010] (3) Weigh a transport agent and mix it with the precursor, and then place it in a second reaction vessel as a secondary reaction raw material.

[0011] (4) Vacuum-seal the second reaction vessel and place it in a two-zone tube furnace. The bottom of the second reaction vessel is located in the high-temperature zone to make the secondary reaction raw material react, and the top of the second reaction vessel is located in the low-temperature zone for heat preservation to grow a single crystal, obtaining a large-sized copper-doped manganese thiophosphate single crystal.

[0012] Preferably, the molar ratio of Cu powder, Mn block, P block and S powder in step (1) is 0.5 - 1.5:0.5 - 1.5:2:6.

[0013] Preferably, the vacuum degree after vacuum-sealing in step (2) is lower than 1 Pa.

[0014] Preferably, the temperature of the high-temperature zone of the two-zone tube furnace in step (2) is 680 - 780 °C, and the temperature of the low-temperature zone is 600 - 680 °C.

[0015] Preferably, the heat preservation time in step (2) is 120 - 240 h.

[0016] Preferably, the transport agent in step (3) is I2 particles, and the addition amount is 3 - 10 mg / cm 3 .

[0017] Preferably, the vacuum degree after vacuum-sealing in step (4) is lower than 1 Pa.

[0018] Preferably, the temperature of the high-temperature zone of the two-zone tube furnace in step (4) is 690 - 770 °C, and the temperature of the low-temperature zone is 590 - 680 °C.

[0019] Preferably, the heat preservation time in step (4) is 120 - 240 h.

[0020] Beneficial effects

[0021] The copper-doped manganese thiophosphate single crystal of this invention exhibits stable chemical properties, and magnetic studies have revealed that it possesses antiferromagnetism at low temperatures and ferroelectricity at room temperature, thus demonstrating its potential applications in spintronics, memory devices, and other fields. The preparation method achieves the controllable synthesis of large-size, high-quality copper-doped manganese thiophosphate single crystals by controlling the raw material molar ratio and a dual-temperature growth environment, providing insights for the study of the physical properties of this material and the fabrication of functional devices. Attached Figure Description

[0022] Figure 1 This is an optical microscope image of the copper-doped manganese thiophosphate single crystal prepared in Example 1.

[0023] Figure 2 The image shows the XRD diffraction spectrum of the copper-doped manganese thiophosphate single crystal prepared in Example 1.

[0024] Figure 3 The graph shows the correlation between the experimental and calculated X-ray diffraction Bragg diffraction integral intensities of the copper-doped manganese thiophosphate single crystal prepared in Example 1.

[0025] Figure 4 The image shows the Raman spectrum of the copper-doped manganese thiophosphate single crystal prepared in Example 1.

[0026] Figure 5 The image shows the X-ray photoelectron spectrum of the copper-doped manganese thiophosphate single crystal prepared in Example 1.

[0027] Figure 6 The image shows the elemental composition analysis energy spectrum of the copper-doped manganese thiophosphate single crystal prepared in Example 1.

[0028] Figure 7 The image shows the magnetic properties of the copper-doped manganese thiophosphate single crystal obtained in Example 1.

[0029] Figure 8 The image shows the ferroelectric diagram of the copper-doped manganese thiophosphate single crystal prepared in Example 1. Detailed Implementation

[0030] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0031] This invention provides a method for preparing large-size copper-doped manganese thiophosphate single crystals, applicable to the preparation of multi-component compound single crystals. The method includes: introducing at least two reactants into a sealed reaction vessel and sealing it under vacuum or a controlled atmosphere; establishing a temperature gradient across the reaction vessel, causing the reactants to react in the high-temperature region and form volatile intermediate species, which migrate along the temperature gradient direction under the action of a transport agent and recrystallize in the low-temperature region, thereby achieving preferential nucleation and continuous growth of the single crystal.

[0032] In this embodiment, the reaction raw materials can be any combination of metallic elements, non-metallic elements, or their compounds, and their proportions can be adjusted according to the stoichiometric relationship of the target compound. The reaction vessel can be a quartz tube or other high-temperature resistant, corrosion-resistant, sealed container.

[0033] In this embodiment, the chemical vapor transport process uses halogens or halides as transport agents, and the type and amount of the transport agent can be selected according to the raw material composition and growth requirements. The temperature range, temperature difference, and holding time between the high-temperature and low-temperature zones can all be controlled according to the required size and quality of the single crystal.

[0034] Using the above method, long-distance transport of raw materials and directional growth of single crystals can be achieved without complex pretreatment, thereby obtaining single crystal materials with large size, high crystal quality and good compositional uniformity.

[0035] It should be understood that the processes and steps involved in this invention are not limited to the examples above. Without affecting the technical effect of this invention, the relevant steps can be adjusted as needed, including but not limited to changing the order of steps, adding or omitting steps, and can also be implemented in parallel or sequential manner; all of these should be considered to fall within the scope of the technical solution of this invention.

[0036] Example 1

[0037] This embodiment provides a method for preparing large-size copper-doped manganese thiophosphate single crystals, including the following steps:

[0038] (1) Weigh 0.172g of Cu powder, 0.142g of Mn block, 0.166g of P block and 0.515g of S powder in a glove box using an electronic balance and place them into the first quartz tube as a mixture. Then, evacuate the inside of the first quartz tube to make the vacuum level inside the first quartz tube lower than 1Pa, and seal the first quartz tube under this vacuum condition.

[0039] (2) The sealed first quartz tube is placed in a dual-temperature zone tube furnace, with the bottom of the first quartz tube in the high-temperature zone and the top in the low-temperature zone. The temperature of the high-temperature zone is controlled at 750℃ and the temperature of the low-temperature zone is controlled at 650℃. The first quartz tube is kept at the above temperature conditions to allow the mixed material to react fully in the high-temperature zone and form a growth precursor in the low-temperature zone under the action of the temperature gradient. The holding time is 120h.

[0040] (3) After obtaining the precursor, weigh 0.010 g of I2 particles and place them together with the precursor into the second quartz tube as raw materials for secondary reaction. Subsequently, the inside of the second quartz tube is evacuated to a vacuum level of less than 0.1 Pa, and the second quartz tube is sealed under this vacuum condition.

[0041] (4) The sealed second quartz tube is placed back into the dual-temperature zone tube furnace, with the bottom of the quartz tube in the high-temperature zone and the top in the low-temperature zone. The temperature of the high-temperature zone is controlled at 750℃, and the temperature of the low-temperature zone is controlled at 650℃. Under the above conditions, a heat preservation treatment is performed to allow the secondary reaction raw materials to undergo a chemical vapor phase transport reaction under the action of temperature gradient and transport agent, and to achieve preferential nucleation and continuous growth of single crystals in the low-temperature zone. The heat preservation time is 120h, thereby obtaining a large-sized and high-quality copper-doped manganese thiophosphate single crystal.

[0042] The morphology, crystal structure, and chemical composition of the copper-doped manganese thiophosphate single crystal prepared in Example 1 were systematically analyzed using various characterization methods, including optical microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy.

[0043] Optical microscopy observations show that, under the above-mentioned process conditions, single crystals with larger size, complete morphology, and smooth surface can be obtained (e.g., Figure 1 As shown). X-ray diffraction results show that the crystal obtained in Example 1 has clear and regular diffraction peaks, and its diffraction characteristics match well with the target crystal structure model, indicating that the prepared material is a single crystal with high crystallinity (e.g., Figure 2 As shown). The experimental and calculated values ​​of the Bragg reflection integral intensity of single-crystal X-ray diffraction show a good linear correlation (e.g., ...). Figure 3 As shown), this further demonstrates the reliability and accuracy of the crystal structure analysis. Raman spectroscopy results (as shown) Figure 4 The vibrational mode characteristics shown are consistent with those of the target crystal, indicating a stable crystal structure and a single phase composition. X-ray photoelectron spectroscopy and energy-dispersive spectroscopy (EDS) analyses (such as...) further confirm this. Figure 5 and Figure 6 As shown, the stoichiometric relationship between the valence state and content of each constituent element in the prepared copper-doped manganese thiophosphate single crystal can be confirmed, and the accurate chemical formula Cu is obtained. 0.71 Mn1.48 P2S6 showed no obvious impurities or elemental segregation, indicating that the method of the present invention can effectively ensure the compositional uniformity and stoichiometric accuracy of the crystal.

[0044] Furthermore, the physical properties of the single crystal prepared in Example 1 were tested. Magnetic test results showed that the copper-doped manganese thiophosphate single crystal exhibited a stable antiferromagnetic order (e.g., ...) at low temperatures. Figure 7 As shown); ferroelectric test results show that the material exhibits clear ferroelectric response characteristics at room temperature (e.g. Figure 8 (As shown). The above results indicate that the copper-doped manganese thiophosphate single crystal prepared in this invention possesses both low-temperature magnetism and room-temperature ferroelectricity, belonging to functional crystal materials with multiferroic characteristics.

[0045] Example 2

[0046] This embodiment provides a method for preparing large-size copper-doped manganese thiophosphate single crystals, including the following steps:

[0047] (1) Weigh 0.174g of Cu powder, 0.153g of Mn block, 0.164g of P block and 0.513g of S powder in a glove box using an electronic balance and place them into the first quartz tube as a mixture. Then, evacuate the inside of the first quartz tube to make the vacuum level inside the first quartz tube lower than 1Pa, and seal the first quartz tube under this vacuum condition.

[0048] (2) The sealed first quartz tube is placed in a dual-temperature zone tube furnace, with the bottom of the first quartz tube in the high-temperature zone and the top in the low-temperature zone. The temperature of the high-temperature zone is controlled at 720℃ and the temperature of the low-temperature zone is controlled at 600℃. The first quartz tube is kept at the above temperature conditions to allow the mixed material to react fully in the high-temperature zone and form a growth precursor in the low-temperature zone under the action of the temperature gradient. The holding time is 140h.

[0049] (3) After obtaining the precursor, weigh 0.009 g of I2 particles and place them together with the precursor into the second quartz tube as raw materials for secondary reaction. Subsequently, the inside of the second quartz tube is evacuated to a vacuum level of less than 0.1 Pa, and the second quartz tube is sealed under this vacuum condition.

[0050] (4) The sealed second quartz tube is placed back into the dual-temperature zone tube furnace, with the bottom of the quartz tube in the high-temperature zone and the top in the low-temperature zone. The temperature of the high-temperature zone is controlled at 760℃, and the temperature of the low-temperature zone is controlled at 670℃. Under the above conditions, a heat preservation treatment is performed to allow the secondary reaction raw materials to undergo a chemical vapor phase transport reaction under the action of temperature gradient and transport agent, and to achieve preferential nucleation and continuous growth of single crystals in the low-temperature zone. The heat preservation time is 130h, thereby obtaining a large-sized and high-quality copper-doped manganese thiophosphate single crystal with the chemical formula Cu. 1.04 Mn 1.58 P2S 5.88 It possesses low-temperature magnetism and room-temperature ferroelectricity similar to those of Example 1.

[0051] Example 3

[0052] This embodiment provides a method for preparing large-size copper-doped manganese thiophosphate single crystals, including the following steps:

[0053] (1) Weigh 0.187g of Cu powder, 0.156g of Mn block, 0.165g of P block and 0.521g of S powder in a glove box using an electronic balance and place them into the first quartz tube as a mixture. Then, evacuate the inside of the first quartz tube to make the vacuum level inside the first quartz tube lower than 1Pa, and seal the first quartz tube under this vacuum condition.

[0054] (2) The sealed first quartz tube is placed in a dual-temperature zone tube furnace, with the bottom of the first quartz tube in the high-temperature zone and the top in the low-temperature zone. The temperature of the high-temperature zone is controlled at 780℃ and the temperature of the low-temperature zone is controlled at 680℃. The first quartz tube is kept warm under the above temperature conditions to allow the mixed material to react fully in the high-temperature zone and form a growth precursor in the low-temperature zone under the action of the temperature gradient. The holding time is 120h.

[0055] (3) After obtaining the precursor, weigh 0.013 g of I2 particles and place them together with the precursor into the second quartz tube as raw materials for secondary reaction. Subsequently, the inside of the second quartz tube is evacuated to a vacuum level of less than 0.1 Pa, and the second quartz tube is sealed under this vacuum condition.

[0056] (4) The sealed second quartz tube is placed back into the dual-temperature zone tube furnace, with the bottom of the quartz tube in the high-temperature zone and the top in the low-temperature zone. The temperature of the high-temperature zone is controlled at 770℃, and the temperature of the low-temperature zone is controlled at 680℃. Under the above conditions, a heat preservation treatment is performed to allow the secondary reaction raw materials to undergo a chemical vapor phase transport reaction under the action of temperature gradient and transport agent, and to achieve preferential nucleation and continuous growth of single crystals in the low-temperature zone. The heat preservation time is 120h, thereby obtaining a large-sized and high-quality copper-doped manganese thiophosphate single crystal with the chemical formula Cu.0.52 Mn 1.74 P2S6 exhibits low-temperature magnetism and room-temperature ferroelectricity similar to those of Example 1.

[0057] In summary, this invention successfully prepared copper-doped manganese thiophosphate single crystals with large size, high crystal quality, precisely resolvable structure, and well-defined stoichiometry using a crystal growth method based on chemical vapor transport. The obtained single crystal material possesses a stable crystal structure and excellent physical properties, showing great application potential in the fields of multiferroic functional materials and related electronic devices.

[0058] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Various modifications, improvements, combinations, or equivalent substitutions made by those skilled in the art based on actual needs without departing from the technical concept and basic principles of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A large-size copper-doped manganese thiophosphate single crystal, characterized in that, The chemical formula of the single crystal is Cu x Mn y P2S6, where 0 < x < 2 and 0 < y < 2; the space group of the single crystal is C2 / m and the size is 4 - 12 mm.

2. A method for preparing large-size copper-doped manganese thiophosphate single crystals, characterized in that, Includes the following steps: (1) Weigh Cu powder, Mn block, P block and S powder and place them in the first reaction vessel to obtain a mixed substance; (2) After the first reaction vessel is vacuum sealed, it is placed in a dual-temperature zone tube furnace. The bottom of the first reaction vessel is located in the high-temperature zone to allow the mixed substances to react, and the top of the first reaction vessel is located in the low-temperature zone to keep warm and grow the precursor. (3) Weigh the transport agent and mix it with the precursor, and then place it in the second reaction vessel as a secondary reaction raw material; (4) After the second reaction container is vacuum sealed, it is placed in a dual-temperature zone tube furnace. The bottom of the second reaction container is located in the high-temperature zone to allow the secondary reaction raw materials to react. The top of the second reaction container is located in the low-temperature zone to keep warm and grow single crystals, thus obtaining large-size copper-doped manganese thiophosphate single crystals.

3. The preparation method according to claim 2, characterized in that, The molar ratio of Cu powder, Mn block, P block and S powder in step (1) is 0.5~1.5:0.5~1.5:2:

6.

4. The preparation method according to claim 2, characterized in that, The vacuum level after vacuum sealing in step (2) is less than 1 Pa.

5. The preparation method according to claim 2, characterized in that, The high-temperature zone of the dual-temperature zone tubular furnace in step (2) has a temperature of 680~780℃, and the low-temperature zone has a temperature of 600~680℃.

6. The preparation method according to claim 2, characterized in that, The heat preservation time in step (2) is 120~240h.

7. The preparation method according to claim 2, characterized in that, The transport agent in step (3) is I2 particles, and the amount added is 3-10 mg / cm³. 3 .

8. The preparation method according to claim 2, characterized in that, The vacuum level after vacuum sealing in step (4) is less than 1 Pa.

9. The preparation method according to claim 2, characterized in that, The high-temperature zone temperature of the dual-temperature zone tubular furnace in step (4) is 690~770℃, and the low-temperature zone temperature is 590~680℃.

10. The preparation method according to claim 2, characterized in that, The heat preservation time in step (4) is 120~240h.

Images