CN114437721B - Rare earth ion Tb 3+ Doped LiTaO 3 Multi-band emission pressure luminescent material and preparation method and application thereof - Google Patents

Abstract

The invention relates to a rare earth ion Tb ³⁺ Doped LiTaO ₃ Multiband emission pressure luminescent material, preparation method and application thereof, and rare earth ion Tb ³⁺ Doped LiTaO ₃ The chemical general formula of the multiband emission pressure luminescent material is Li _1‑x TaO ₃ :xTb ³⁺ Wherein x is more than or equal to 0.005 and less than or equal to 0.03.

Description

A rare earth ion Tb3+ doped LiTaO3 multi-band emission pressure luminescent material and its preparation method and application

technical field

The invention relates to a rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission pressure luminescence material and a preparation method and application thereof, belonging to the technical field of optical functional materials and the field of stress luminescence.

Background technique

Under the action of external mechanical stress (such as friction, impact, compression, stretching, bending, twisting, scraping, grinding, cutting, cracking, etc.), the stress luminescent material can release the stored energy in the form of luminescence. Stress sensing, lighting and display driven by mechanical force, artificial intelligence skin, safety and health diagnosis of structural parts and many other fields have broad application prospects, and have attracted extensive attention from domestic and foreign researchers. The phenomenon of stress luminescence was first discovered and recorded in sugar crystal blocks in 1605. In 1998, Akiyama et al. reported green stress luminescence visible to the naked eye in Sr ₃ Al ₂ O ₆ :Eu,Dy phosphor, and the luminous intensity was close to 500 times that of sugar crystal blocks (Applied Physics Letters, 1998, 3046(73): 3046-3048). In 1999, Chaonan Xu et al. reported orange stress luminescence in ZnS:Mn nanoparticle films (Journal of the American Ceramic Society, 1999, 82(9):2342-2344). Subsequently, stress luminescence has been reported in a variety of materials.

At present, the more effective inorganic stress luminescence substrates include strontium aluminate (SrAl ₂ O ₄ ), lithium niobate (LiNbO ₃ ), zinc sulfide (ZnS) and calcium zinc oxysulfide (CaZnOS). The generation of stress luminescence depends on the host material and the selected dopant luminescent ions. For example, in SrAl ₂ O ₄ , green stress luminescence is mainly achieved by doping divalent europium ions (Eu ²⁺ ); in LiNbO ₃ , the main Red stress luminescence is achieved by doping trivalent praseodymium ions (Pr ³⁺ ); in ZnS, red and green stress luminescence are mainly achieved by doping transition metal ions (Mn ²⁺ , Cu ²⁺ ). However, the preparation technology of the above materials needs to be improved. On the one hand, the synthesis conditions of SrAl ₂ O ₄ :Eu ²⁺ and CaZnOS are complex and require atmosphere treatment, which further increases the manufacturing cost, which is not conducive to commercialization and application, and the waterproofness of the synthesized products The performance is poor, and the absorption of moisture in the air will greatly reduce the optical performance, which limits the practical application; After a single application of pressure, the stress luminescence will disappear, and it needs to be excited again with ultraviolet light to restore the stress luminescence performance. Therefore, it is of great significance to develop stress-luminescent materials with high efficiency, stability, multi-band emission and sustainable stress-luminescence.

Contents of the invention

In order to overcome the deficiencies in the prior art, the purpose of the present invention is to provide a rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band pressure luminescent material and its preparation method and application.

In one aspect, the present invention provides a rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission piezoluminescent material, the chemical general formula of the rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission piezoluminescent material is Li _1-x TaO ₃ :xTb ³⁺ , where 0.005≤x≤0.03.

In this disclosure, when the doped trivalent rare earth ions Tb ³⁺ enter the LiTaO ₃ host lattice, they replace the monovalent Li ⁺ ion site, and the imbalance of the asymmetric substitution valence makes it produce a partial in the forbidden band. The localized energy state is the trap level. The stress luminescence mechanism is that electrons are excited to transition after irradiation, and the carriers are captured by the trap energy level and stored stably. When the external stress is applied again, the trap energy level moves to the conduction band due to the distortion of the geometric structure, so that the carriers can jump to the conduction band, and finally return to the ground state to realize stress luminescence, corresponding to the parity forbidden ff transition of Tb ³⁺ feature launch.

Preferably, 0.005≤x≤0.02, and the intensity of the stress luminescence increases first, then decreases, and reaches the optimum when x=0.01.

Preferably, the pressure luminescence spectrum of the rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission pressure luminescence material is multi-band emission from blue light to orange light, and the emission center wavelengths are 487nm, 541nm, 583nm and 618nm, respectively. Corresponding to ⁵ D ₄ → ⁷ F ₆ , ⁷ F ₅ , ⁷ F ₄ and ⁷ F ₃ transitions of Tb ³⁺ . Moreover, the rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission pressure luminescent material obtained in the present invention still has excellent luminescent performance after repeated pressure application between 0 and 2000N, has high luminous intensity, high sensitivity, and can Advantages such as recovery (i.e., excellent pressure-luminescence cycling stability).

On the other hand, the present invention provides a kind of preparation method of above-mentioned rare earth ion Tb ³⁺ doped LiTaO ₃ piezoluminescence material, comprising:

(1) The lithium source, tantalum source and terbium source are weighed and mixed according to the molar ratio of the elements as Li:Ta:Tb=1-x:1:x, and pre-calcined at 500-900°C in an air atmosphere to obtain a pre-calcined burning powder;

(2) Calcining the obtained calcined powder in an air atmosphere at 1000-1400° C. to obtain the LiTaO ₃ piezoluminescent material doped with rare earth ions Tb ³⁺ .

In the present invention, the lithium source, the tantalum source and the terbium source are mixed and then calcined to promote diffusion. Calcination is then carried out to cause a solid-state reaction to occur, and finally a LiTaO ₃ piezoluminescent material doped with rare earth ions Tb ³⁺ is obtained.

Preferably, the lithium source is a lithium-containing compound, preferably at least one of lithium oxide, lithium carbonate, lithium nitride and lithium carbide.

Preferably, the tantalum source is a compound containing tantalum, preferably at least one of tantalum pentoxide and tantalum powder.

Preferably, the terbium source is a terbium-containing compound, preferably at least one of tetrabium heptoxide, terbium acetate, terbium sulfate, terbium fluoride and terbium powder.

Preferably, the heating rate of the pre-burning is 3-10° C./minute.

Preferably, the pre-burning time is 2-8 hours.

Preferably, the heating rate of the calcination is 2-10° C./min.

Preferably, the calcination time is 5-15 hours.

In yet another aspect, the present invention provides a stress distribution monitoring and failure warning, a stress sensor, a stress _display , an ultra ^- precise device applications.

Beneficial effect:

In the present invention, a novel multi-band emission pressure luminescent material and its preparation method are provided, that is, LiTaO ₃ doped with trivalent rare earth ions Tb ³⁺ , adopting a two-step heat treatment solid-phase synthesis method, the preparation process is simple, and no atmosphere is required Treatment and preparation conditions are easy to control;

In the present invention, the luminescent spectrum of LiTaO:Tb ³⁺ pressure luminescent material covers multi-band emission from blue light to orange light (487nm, 541nm, 583nm and 618nm), and it still has luminescent performance after multiple cycles of pressure from 0 to 2000N. High luminous intensity, high sensitivity, recoverable and so on.

Description of drawings

Fig. 1 is the X-ray diffraction pattern of Li _1-x TaO ₃ :xTb ³⁺ (x=0.005, 0.01, 0.015 and 0.02) piezoluminescence materials doped with different Tb ³⁺ concentrations prepared in Examples 1-4 ( XRD), the standard X-ray diffraction spectrum of the _LiTaO3 phase is inserted at the bottom of the figure;

Figure 2 shows the luminescence of Li _1-x TaO ₃ :xTb ³⁺ (x=0.005, 0.01, 0.015 and 0.02) stress luminescent materials doped with different Tb ³⁺ concentrations prepared in Examples 1-4 under a pressure of 2000N spectrum;

Fig. 3 is a diagram of the luminous intensity of the Li _0.995 TaO ₃ :0.005Tb ³⁺ (x=0.005) pressure luminescent material prepared in Example 1 under the pressure outside the cycle of 0-2000N;

Fig. 4 is a diagram of the luminous intensity of the Li _0.995 TaO ₃ :0.01Tb ³⁺ (x=0.01) pressure luminescent material prepared in Example 2 under the pressure outside the cycle of 0-2000N;

Fig. 5 is a diagram of the luminous intensity of the Li _0.995 TaO ₃ :0.015Tb ³⁺ (x=0.015) pressure luminescent material prepared in Example 3 under the pressure outside the cycle of 0-2000N;

Fig. 6 is a diagram of the luminous intensity of the Li _0.995 TaO ₃ :0.02Tb ³⁺ (x=0.02) pressure luminescent material prepared in Example 4 under the pressure outside the cycle of 0-2000N.

Detailed ways

The present invention will be further described below through the following embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, not to limit the present invention.

In the present disclosure, the general chemical formula of the rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission piezoluminescent material can be Li _1-x TaO ₃ :xTb ³⁺ , wherein the molar number x of the rare earth ion Tb ³⁺ takes the value The range is 0.005≤x≤0.03, preferably 0.005≤x≤0.02, more preferably 0.0075≤x≤0.015, most preferably x=0.01.

The preparation method of the rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission pressure luminescent material provided by the present invention is exemplarily described below.

Choose ingredients. Compounds containing lithium, tantalum and terbium are selected as raw materials. The lithium-containing compound may be any one of lithium oxide, lithium carbonate, lithium nitride and lithium carbide. The raw material of the compound containing tantalum is any one of tantalum pentoxide and tantalum powder. The raw material of the compound containing terbium is any one of tetrabium heptoxide, terbium acetate, terbium sulfate, terbium fluoride and terbium powder.

ingredients. The compound raw materials containing lithium, tantalum and terbium are weighed and mixed in a molar ratio of 1-x:1:x, wherein the range of x is 0.005≤x≤0.03, and mixed uniformly to obtain a mixed powder.

pre-burn. The mixed powder is pre-fired in an air atmosphere at 500-900°C until the powder is pre-fired. Preferably, after pre-burning is completed, it is taken out after cooling and ground again. As an example of pre-burning, weigh the raw materials strictly according to the molar ratio, mix them evenly, put them into the muffle furnace and increase the temperature from room temperature to 500-900°C at a rate of 3-10°C/min. Pretreat for 2-8 hours, and obtain calcined powder after cooling.

calcined. The calcined powder is then calcined in an air atmosphere at a calcining temperature of 1000-1400°C; finally cooled to room temperature with the furnace. Grind the calcined powder again, put it into a muffle furnace, raise the temperature from room temperature to a calcination temperature of 1000-1500 ℃ at a rate of 2-10 ℃/min, and calcine in an air atmosphere for 5-15 hours.

In the present invention, the pressure luminescence spectrum of the obtained LiTaO ₃ : Tb ³⁺ covers multi-wavelength emission from blue light to orange light (487nm, 541nm, 583nm and 618nm), and it still has luminescence performance after multiple cycles of pressure from 0 to 2000N, With the advantages of high luminous intensity, high sensitivity, and recoverability, it has important practical application value in application scenarios such as stress distribution monitoring and failure warning of organisms, mechanical parts and buildings, stress sensors, stress displays, and ultra-precision device processing. At the same time, the preparation condition of the present invention is mild, the operation is relatively simple, and it is easy to realize large-scale production.

Examples are given below to describe the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the above contents of the present invention all belong to the present invention scope of protection. The specific process parameters and the like in the following examples are only examples of suitable ranges, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values exemplified below.

Example 1

According to the molar ratio of each element Li:Ta:Tb=0.995:1:0.005 (equivalent to Tb doping amount x=0.005), lithium carbonate, tantalum oxide and tetraterbium heptoxide were selected as raw materials, and the weighing amount was 0.3676g , 2.2097g and 0.0094g. Fully grind in an agate mortar for 1 hour to make it mix uniformly to obtain a mixed powder. Put the mixed powder into a muffle furnace, raise the temperature from room temperature to 600°C at a rate of 5°C/min, pretreat for 2 hours in an air atmosphere, and obtain calcined powder after cooling. Grind the calcined powder again, put it into a muffle furnace from room temperature to a calcination temperature of 1100°C at a rate of 3°C/min, calcinate in an air atmosphere for 5 hours, and cool down to room temperature with the furnace to obtain Li _0.995 TaO ₃ : 0.005Tb ³⁺ (x=0.005) pressure luminescence powder. The synthetic powder has high crystallinity, as shown in the XRD diffraction phase analysis results shown in Figure 1. It is detected that the pressure luminescent material prepared in this embodiment has a luminous emission peak of a line spectrum under a pressure of 2000N, and has blue light emission at 487nm, green light emission at 541nm, yellow light emission at 583nm and Orange light emission at 618nm, see the pressure emission spectrum analysis results shown in Figure 2.

Example 2

On the basis of Example 1, the Tb ³⁺ doping amount is increased. According to the molar ratio of each element Li:Ta:Tb=0.99:1:0.01 (equivalent to Tb doping amount x=0.01), lithium carbonate, tantalum oxide and tetraterbium heptoxide were selected as raw materials, and the weighing amount was 0.3621g , 2.2097g and 0.0187g were fully ground in an agate mortar for 1 hour, and mixed evenly to obtain a mixed powder. Put the mixed powder into a muffle furnace, raise the temperature from room temperature to 600°C at a rate of 5°C/min, pretreat for 2 hours in an air atmosphere, and obtain calcined powder after cooling. Grind the calcined powder again, put it into a muffle furnace from room temperature to a calcination temperature of 1100°C at a rate of 3°C/min, calcinate in an air atmosphere for 5 hours, and cool down to room temperature with the furnace to obtain Li _0.990 TaO ₃ : 0.01Tb ³⁺ (x=0.01) pressure luminescence powder. The synthetic powder has high crystallinity, as shown in the XRD diffraction phase analysis results shown in Figure 1. It is detected that the pressure luminescent material prepared in this embodiment has a luminous emission peak of a line spectrum under a pressure of 2000N, and has blue light emission at 487nm, green light emission at 541nm, yellow light emission at 583nm and Orange light emission at 618nm, see the pressure emission spectrum analysis results shown in Figure 2. And the pressure luminescence intensity is significantly enhanced compared with Example 1.

Example 3

In Example 3, the preparation process of the rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission piezoluminescence material refers to Example 2, the difference is: x=0.015. See the XRD diffraction phase analysis results shown in Figure 1. It is detected that the pressure luminescent material prepared in Example 3 has a luminous emission peak of a line spectrum under a pressure of 2000N, and has blue light emission at 487nm, green light emission at 541nm, and yellow light emission at 583nm. As well as the orange light emission at 618 nm, see the pressure emission spectrum analysis results shown in FIG. 2 .

Example 4

On the basis of Example 2, the Tb ³⁺ doping amount is further increased. According to the molar ratio of each element Li:Ta:Tb=0.9801:0.02 (equivalent to Tb doping amount x=0.02), lithium carbonate, tantalum oxide and tetraterbium heptoxide were selected as raw materials, and the weighing amounts were 0.3584g and 2.2097g respectively. g and 0.0374g, fully grind it in an agate mortar for 1 hour, and make it mix uniformly to obtain a mixed powder. Put the mixed powder into a muffle furnace from room temperature to 600°C at a rate of 5°C/min, pretreat it in an air atmosphere for 2 hours, and obtain calcined powder after cooling. Grind the calcined powder again, put it into a muffle furnace and increase the temperature from room temperature to 1100 °C at a rate of 3 °C/min, calcinate in an air atmosphere for 5 hours, and cool to room temperature with the furnace to obtain Li _0.980 TaO ₃ : 0.02Tb ³⁺ (x=0.02) pressure luminescence powder. See the XRD diffraction phase analysis results shown in Figure 1. It is detected that the pressure luminescent material prepared in this embodiment has a luminous emission peak of a line spectrum under a pressure of 2000N, and has blue light emission at 487nm, green light emission at 541nm, yellow light emission at 583nm and Orange light emission at 618nm, see the pressure emission spectrum analysis results shown in Figure 2.

Fig. 1 is the X-ray diffraction pattern of Li _1-x TaO ₃ :xTb ³⁺ (x=0.005, 0.01, 0.015, 0.02) piezoluminescence materials doped with different Tb ³⁺ concentrations prepared in Examples 1-4 ( XRD), the standard X-ray diffraction spectrum of the _LiTaO3 phase is inserted at the bottom of the figure. From the figure, it can be seen that the diffraction peaks of the synthesized sample correspond well to the standard card, that is, the synthesized sample is a pure phase.

Figure 2 shows the luminescence of Li _1-x TaO ₃ :xTb ³⁺ (x=0.005, 0.01, 0.0015 and 0.02) stress luminescent materials doped with different Tb ³⁺ concentrations prepared in Examples 1-4 under a pressure of 2000N It can be seen from the figure that its luminous emission peak is a linear spectrum, and has blue light emission at 487nm, green light emission at 541nm, yellow light emission at 583nm and orange light emission at 618nm. The four peaks correspond to Tb The characteristic emission of ³⁺ ions, and the luminous intensity increases first and then decreases with the doping concentration.

Figures 3, 4, 5, and 6 are Li _1-x TaO ₃ :xTb ³⁺ (x=0.005, 0.01, 0.015, and 0.02) piezoluminescent materials doped with different Tb ³⁺ concentrations prepared in Examples 1-4 The luminous intensity diagram under 10 cycles of external pressure from 0 to 2000N can be seen from the figure that the stress luminescence is the strongest when the load is applied for the first time, and gradually decreases with the increase in the number of applied loads, but still has a certain emission intensity. It shows that under the action of stress, the material can emit strong pressure luminescence, and still has a certain luminescence intensity after ten cycles of compression, that is, the pressure luminescence intensity can be restored, indicating that the material has excellent luminescence recoverability. At the same time, after the large stress is applied, the afterglow of the pressure luminescence decays rapidly, which is timely. By comparison, it is found that Li _1-x TaO ₃ :xTb ³⁺ (x=0.01) has the best cycle performance, and still has the highest luminous intensity after 10 times of pressure.

Finally, it is necessary to explain here that: the above examples are only used to further describe the technical solutions of the present invention in detail, and cannot be interpreted as limiting the protection scope of the present invention. Essential improvements and adjustments all belong to the protection scope of the present invention.

Claims (12)

1. A rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission piezoluminescent materials, characterized in that, the rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission piezoluminescent materials have a general chemical formula of Li _{1 -x} TaO ₃ :xTb ³⁺ , wherein 0.005≤x ≤0.02; the pressure luminescence spectrum of the rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission pressure luminescent material is multi-band emission from blue light to orange light, and its emission The central wavelengths are 487nm, 541nm, 583nm and 618nm, respectively. 2. The rare earth ion Tb ³⁺ doped LiTaO ₃ multi-band emission pressure luminescent material according to claim 1, characterized in that x=0.01. 3. a kind of rare earth ion Tb described in claim 1 or 2 ^LiTaO doped LiTaO ₃ preparation method of piezoluminescence material, it is characterized in that, comprising: (1) The lithium source, tantalum source and terbium source are weighed and mixed according to the molar ratio of the elements as Li:Ta:Tb=1-x:1:x, and pre-calcined at 500-900°C in an air atmosphere to obtain a pre-calcined burning powder; (2) Calcining the obtained calcined powder in an air atmosphere at 1000-1400° C. to obtain the LiTaO ₃ piezoluminescent material doped with rare earth ions Tb ³⁺ . 4. The preparation method according to claim 3, characterized in that, the lithium source is a lithium-containing compound. 5. The preparation method according to claim 4, wherein the lithium source is at least one of lithium oxide, lithium carbonate, lithium nitride and lithium carbide. 6. The preparation method according to claim 3, characterized in that, the tantalum source is a compound containing tantalum. 7. The preparation method according to claim 6, wherein the tantalum source is at least one of tantalum pentoxide and tantalum powder. 8. The preparation method according to claim 6, characterized in that, the terbium source is a terbium-containing compound. 9. The preparation method according to claim 8, wherein the terbium source is at least one of terbium heptoxide, terbium acetate, terbium sulfate, terbium fluoride and terbium powder. 10. The preparation method according to claim 3, characterized in that, the heating rate of the pre-calcination is 3-10° C./minute; the time of the pre-calcination is 2-8 hours. 11. The preparation method according to any one of claims 3-10, characterized in that, the heating rate of the calcination is 2-10° C./min; the calcination time is 5-15 hours. 12. A kind of rare earth ion Tb ³⁺ doped LiTaO ₃ pressure luminescence material described in claim 1 or 2 in the stress distribution monitoring and failure warning of organisms, mechanical parts and buildings, stress sensor, stress display, ultra-precision device applications.

Images