TWI344485B - Terbium aluminum garnet powder and method for making the same - Google Patents

Description

1344485 IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to a fluorescent powder and a method for producing the same, and in particular to a erbium aluminum garnet (TAG) powder And its manufacturing method. [Prior Art] Fluorescent powder has been used in illuminating and display products for half a century. The type of 吁 + + phosphor powder has reached more than 3G, which can be roughly divided into: organic camp light powder, camping pigment 'inorganic phosphor powder and radioactive elements. Recently, the most popular application area for phosphor powder is the Light Emitting Diode (LED). Due to the small size, no heat radiation, low power consumption, long life and good reaction speed of white LEDs, it can solve many problems that are difficult to overcome in the past. When the phosphor powder is applied to a white LED, the white light forming principle utilizes two-wavelength mixed light and three-wavelength mixed light. The two-wavelength mixed light mainly uses blue light to excite the B-color fluorescent powder to mix the blue-yellow two-color light into white light. The material of the yellow fluorescent powder used is Yttrium Aluminum Garnet (YAG:Ce) containing yttrium and yttrium-containing yttrium. The triallite stone (Terbium Aiuminum Garnet; TAG: Ce) dominates. Since the light excited by yttrium aluminum garnet is cool white light, it needs to be doped with rare earth (Rare Earth) element, and its illuminating wavelength is shifted toward the visible light region (ie, long wavelength region), and is adjusted to warm white light. The yttrium aluminum garnet is warm white light due to its own light, and it does not need to be adjusted to adjust its brightness, color rendering and color temperature to be much better than YAG. Conventional production of yttrium aluminum garnet powder is generally carried out by chemical methods such as immersion 5 1344485 ash method, S〇i_Gel Method, hydrothermal method and combustion method, or solid phase reaction method. The conventional solid-phase reaction method is obtained by ball milling and repeated calcination using materials such as oxidation test (Dingta). (4) Although the synthesis temperature of the reaction method is low, it is inevitable that many waste water and waste liquid will be discharged. In addition, the light obtained by these methods is cold white light. Accordingly, it is necessary to develop a yttrium aluminum garnet powder and a method for producing the same to improve various disadvantages of the conventional gj phase reaction method and the liquid phase reaction method. Φ'Φ [Summary of the Invention] Therefore, the object of the present invention is to provide a yttrium aluminum garnet (TAG) powder having a chemical structure of Τ]33·χΑΐ5〇ΐ2: Μχ, wherein Μ For example, 钸, 铕, 铥, 铌, 镱, 釓 or other rare earth elements, and 〇SXS 0.5, and the yttrium aluminum garnet powder has an emission wavelength (Emissi〇n • Wavelength) between 540 nm and 560 nm. between. According to the above object of the present invention, a garnet powder is prepared, and the garnet powder system is formed by coating a core-shell structure formed by coating an aluminum-containing compound on the surface of the cerium oxide through a high-temperature burning step. The chemical structure formula of the aluminum garnet powder is Tb3-xAl5〇u:Mx, wherein the lanthanide is selected from the group consisting of 钸, 铕 'chain, 铌, 镜' 釓, 〇Sx$〇5. The chemical structural formula of the above aluminum-containing compound may be, for example, A100H·yH2〇, wherein. According to the above object of the present invention, a method for producing yttrium aluminum garnet (TAG) powder is further proposed. The aluminum garnet powder system utilizes an acid aging step to form a core shell by coating a surface containing a compound with cerium oxide. The structure is thereby effective in reducing the diffusion distance of the aluminum-containing compound from the cerium oxide in the subsequent solid phase reaction 6 1344485. In this way, not only the purity of the yttrium aluminum garnet powder obtained after sintering, but also the uniform particle size, the fluorescence intensity is higher, and the processing time of the yttrium aluminum garnet powder is greatly shortened. The above-described core-shell structure is formed by a pH of less than or equal to 3. It can be seen from the above that the test aluminum garnet (TAG) powder of the present invention and the method for producing the same use the acid aging step to coat the surface of the cerium oxide with an aluminum-containing compound to form a core-shell structure. The subsequent diffusion of the aluminum compound and cerium oxide is effectively reduced in the subsequent solid phase reaction. In this way, not only the obtained Shaoshiquan stone powder has high purity, uniform particle size, high labor intensity, and greatly shortens the processing time of the yttrium aluminum garnet powder. [Embodiment] As described above, the present invention provides a yttrium aluminum garnet (TAG) powder and a method for producing the same, wherein an aluminum-containing compound is coated on a surface of a cerium oxide to form a core-like structure by an acidic aging step. In order to effectively reduce the diffusion distance between the aluminum-containing compound and the cerium oxide in the subsequent solid phase reaction, the obtained yttrium aluminum garnet powder has a relatively uniform enthalpy granule, and the fluorimetric intensity is high, and the yttrium aragonite is greatly shortened. The processing time of the powder. The details of the present invention will be described below by way of a preferred embodiment. The samarium garnet (Terbium Aluminum Garnet; TAG) of the present invention has a structure of Tb3 χΑΐ5〇ΐ2: Μ" wherein M can be decorated, pinned, chained, chaotic or other rare earth elements, however The invention is not limited to the above: in addition to 〇.5. In other words, the yttrium aluminum garnet powder system is formed by coating the surface of the 氡化锋 with 3 inscriptions, and the core-shell structure is formed by high temperature calcination/squeeze. The chemical formula containing the above-mentioned compound can be, for example, 1344485 〇Η 0 〇Η yH20, wherein 〇Sy$3. In particular, the aluminum-containing compound may include, but is not limited to, aluminum oxide or aluminum hydroxide, wherein the aluminum oxide may include, but is not limited to, alpha phase alumina, zero phase alumina or r phase alumina; and aluminum hydroxide may include, but is not limited to, Shao argon oxide or soft aluminum stone. In the manufacture of the yttrium aluminum garnet powder, the bismuth oxide, the aluminum-containing compound, and the gasified ruthenium can be firstly weighed according to the chemical agent ratio of Tb(3x)Al5〇i2:Mx. Depending on the demand, when X is equal to 0, the yttrium aluminum garnet powder obtained by the present invention may be free of rare

Tu nationality. However, when x is not equal to 0, the yttrium aluminum garnet powder obtained by the present invention has a rare earth element having an unequal content, and the luminescent wavelength can be elastically adjusted. Next, an acidic aging step is carried out in which the above-mentioned aluminum-containing compound, cerium oxide and gasified cerium are uniformly mixed with about 5 weight percent of deionized water to form a slurry. Next, the acidity and alkalinity of the above slurry is adjusted to 3 or less by using a pH adjuster such as a mineral acid or an organic acid to form an acidic slurry. Suitable inorganic acids may be, for example, nitric acid (HNO3), sulfuric acid (h2S04), phosphoric acid (H3P〇4) or carbonic acid (H2C〇3). Suitable organic acids may be, for example, acetic acid (CH3CO〇H) or the like.

It is worth mentioning that in the acidic environment with a pH value of less than or equal to 3, the aluminum-containing compound will coat the surface of the cerium oxide to form a core-shell structure, thereby effectively reducing the subsequent solid phase reaction. The diffusion distance of the aluminum-containing compound and cerium oxide. Before the subsequent high-temperature calcination step, the drying step may be selectively performed to remove the deionized water of the acidic slurry. The suitable drying step may be, for example, a S-known process, such as oven drying or centrifugal drying. Used in this step to remove the deionized water of the above acidic slurry. Thereafter, a high-temperature calcination step is performed to form a desired yttrium aluminum garnet powder, wherein the calcination temperature is substantially between ^(8)^ and 1600t, 8 1344485, however, the temperature is substantially between the curse Preferably, the art is between 155 Torr and the calcining time is from 5 hours to 48 hours, but this time is preferably from 24 hours to 42 hours. After the above calcination step, the obtained yttrium-aluminal powder may have an emission wavelength of between 540 nm and 560 nm. The following is a list of preferred embodiments and the following figures to FIG. 4, in order to explain in more detail the application of the yttrium aluminum garnet powder of the present invention and a method for producing the same, which are not intended to limit the present invention, and therefore The scope of the invention is defined by the scope of the appended claims. In the first embodiment, about 0,1 weight percent (〇% by weight) of cerium oxide or about 〇% by weight of cerium oxide and soft aluminum stone, respectively, with ammonium hydroxide to adjust its pH value to about 12, and then The nitrate was titrated and adjusted to a pH of about 3, and the surface potential was measured by sampling during the titration. Thereafter, the above acidified mixed slurry (cerium oxide with or without soft-alumina) is titrated with ammonium hydroxide and the pH value thereof is adjusted to about 12, and the surface potential is continuously sampled and measured during the titration. The change in (ς potential) and the equipotential point (IS〇_ElectHc Point; LE.P·) is obtained according to the result. The surface potential changes measured by the two are shown in Fig. 〖(a) and Fig. 1(b). "monthly,', Fig. 1(a), which is a graph showing the relationship between the surface potential of the oxidation test and the pH value of the comparative example. It can be seen from the i-th (4) diagram that the S (test value (PH) (4) oxygen series is adjusted by the ammonium hydrogen halide, and the isoelectric point (iEp) falls about 8 to the acid value. 〃明参,,,,1(b) The figure shows the relationship between the surface potential and the acid value of a combination of yttrium oxide and soft shoal according to the preferred embodiment of the present invention. The figure (b) shows that the sputum test is soft and soft. The acid value of the Mingshi mixed material is adjusted from about 1344485 to about 3, and the equipotential point is about 6; however, the acid value of the oxidized domain and the soft mixed stone slurry is adjusted back from about 3 to about When u, the equipotential point changes from about 6 to about 9. Since the equipotential point of the soft inscription falls on the acid value of about 9, it is known from the results of the first (8) figure that after the acid aging step Soft. 33 stone will cover the surface of (10) oxygen (4), and the pH value of the oxygen field and the (tetra) stone will change from the equipotential point of yttrium oxide to the isoelectric point of soft alumina. Example 2 firstly according to Tb2 The chemical dose ratio of .95Al5〇12. Ce〇.〇5 is calculated by taking appropriate amount of oxygen Φ test, soft Mingshi and gasification 钸. Mix soft shoal with about 5 wt% deionized water to form H Next, the acid aging step is carried out, that is, the 1M nitric acid (HN〇3) is slowly dropped into the preparation, and the pH value of the batch is adjusted to about 3 for about 5 minutes to form an acidic slurry. The slurry is in the form of a gel. Alternatively, the slurry may be subjected to a non-acidic aging step as a comparative example. Next, cerium oxide and cerium chloride are added to the (or not) acidic aging step. In the slurry, wherein the acidic slurry can uniformly coat the soft alumina on the surface of the cerium oxide, forming a core-shell structure. Then, depending on the case, the drying step can be performed by an oven to remove the above acidity (4) The dehydrated water was dehydrated to form a dry powder. Thereafter, the dried powder obtained above was further calcined at 12 Torr for 2 hours and calcined at 1501 for 36 hours, and the results are shown in Fig. 2. ®, which shows an X-ray diffraction (XRay Di-valent acti〇n; xRD) pattern of a test aluminum garnet powder according to another preferred embodiment of the present invention, wherein the vertical axis represents the intensity (cps), and The horizontal axis indicates the scanning angle.). In Fig. 2, 'G is not TAG phase, p is 铽 aluminum pseudocube crystal (7) plus (10) AIuminum Perovskite; TAp; TbA 〇 3) is the intermediate phase and M is 铽 1344485 singular monoclinic (Terbium Aluminum Monoclinic; ΤΑΜ The intermediate phase of Tb4Al2〇9), curve (a) represents the control group without the acid aging step, and curve (b) represents another preferred embodiment of the acid aging step. From the results of Fig. 2, it is known that the yttrium-containing yttrium aluminum garnet powder [i.e., curve (b)]' treated by the acid aging step has been converted into a tag phase by the intermediate phase of TAM and tap. In contrast, the yttrium-containing yttrium aluminum garnet powder [ie, curve U)] is not treated by the acid aging step, and the diffraction peaks not only remain in the mesophase of ruthenium and TAP, but also the diffraction peak of alumina appears. 》

Example 3 First, an appropriate amount of oxidation test, soft stone and oxidation pin were weighed according to the chemical dose ratio of TbwAlsO, 2: EuG. The soft chain stone is mixed with about 5 weight percent deionized water to form a slurry. Next, the acid aging step is carried out, that is, slowly dropping into the slurry by using 1 M nitric acid (HN〇3), adjusting the pH value of the slurry to about 3, and maintaining for about 5 minutes to form an acidic slurry, which is acidic. The slurry is in the form of a gel. Alternatively, the slurry may be subjected to an acid-free aging step as a comparative example.

Next, bismuth telluride and cerium oxide are added to the acidic slurry to uniformly coat the soft alumina on the surface of the cerium oxide to form a core-shell structure. Then, depending on the situation, a drying step may be carried out by using a baking phase to remove the deionized water of the above acidic slurry to form a dry powder. Thereafter, the above-mentioned light source of the (four) (four) wave obtained by the above-mentioned "heating" is irradiated and the light-emitting wavelength is measured, and the result is shown in FIG. 3. Referring to FIG. 3, there is shown a further preferred embodiment of the present invention. — Phosphorus (Ph〇t〇luminescence; pL) spectrum of yttrium aluminum garnet powder, the vertical axis of which shows the luminous intensity (A_咖y Unit; au·), and the horizontal axis shows the length (10)).

Curve (a) shows a control group which is not subjected to the acid aging step, and curve (b) shows a further preferred embodiment of the acid aging step. From the results of Fig. 3, it is known that the non-acidic aging step of treating the yttrium-containing yttrium aluminum garnet powder does not have the fluorescent powder property. Under the illumination of a light source having a wavelength of 470 nm, no luminescent wavelength is generated, such as a curve (a ) as shown. In contrast, the treatment of the yttrium-containing yttrium-aluminum powder by the acid aging step has a fluorescent powder property, and its fluorescence intensity is irradiated by a light source having a wavelength of 470 nm, and its illuminating wavelength is 54 〇. Between 11111 and 56〇nm, it is warm white light, as shown by curve (b). Example 4: cerium oxide powder which has not been subjected to an acid aging step, cerium oxide powder which has been subjected to an acid aging step, cerium oxide mixed with soft boehmite which has not been subjected to an acid aging step, and an acid aging step The powder of cerium oxide and soft alumina was mixed, and the surface morphology and particle size of the powder were further analyzed by a scanning electron microscope at a magnification of 5000 times. The results are shown in Figures 4(a) to 4(d). "Monthly refer to Figures 4(a) to 4(d), where Figure 4(a) shows a scanning electron micrograph of cerium oxide powder without an acid aging step, Figure 4(b) Scanning electron micrograph of cerium oxide powder for the aging step, the fourth is a scanning electron micrograph of the mixed powder of cerium oxide and soft alumina without the acid aging step, 4th (d) is a scanning electron micrograph of a mixed powder of cerium oxide and soft alumina according to still another preferred embodiment of the present invention. From 囷, the cerium oxide powder is not subjected to the acid aging step. The shape of the body is a long strip type, and its particle size is about 4 μm. After the acid aging step, part of the shape of the cerium oxide powder is also disintegrated from the original strip into a smaller rod. And its particle size is decomposed into about 2~3μπι, as shown in Figure 4(b). A similar situation can be seen in Figure 4(c), oxidizing 12 1344485 before the acid aging step

Two types of powders can be observed in the mixed powder of soft and shale. One is the granular shape of the soft Ming stone, and the other is the long strip of yttrium oxide. The two are separated from each other. . Therefore, when the solid phase reaction is carried out at a high temperature, the diffusion distance is long, and the yttrium garnet powder can be synthesized under the conditions of high temperature and long time. However, in the fourth (d) figure, the soft alumina is coated on the bismuth telluride powder, and the mixed powder of the two retains the morphology of the bismuth test powder. According to the fourth (Ten), the cerium oxide powder can be decomposed into finer particles by the acidic aging step of the present invention, and the refining process not only effectively reduces the diffusion distance between the particles and the particles, so that It is easier to obtain uniform particles in the solid phase reaction, and the test aluminum garnet powder can be obtained in a shorter time. In short, after the above results are simplified into the fifth (a) and the fifth (b), 5(a) is a schematic view showing a mixed powder of cerium oxide and an aluminum oxide-containing composite which is not subjected to an acid aging step, and FIG. 5(b) is a view showing still another preferred embodiment of the present invention. A schematic diagram of a mixed powder of cerium oxide and an aluminum-containing oxide. The cerium oxide and the aluminum-containing oxide mixed powder which are obtained without the acid aging step, which are obtained from the fifth (a), are separated from each other. According to the figure 5(b), after the acid aging step, the aluminum-containing bismuth compound is coated on the bismuth telluride powder. According to the above four preferred embodiments, the acid aging according to the present invention is known. After the step of treating the emulsified enamel and the mixed compound containing the compound, the compound may be coated on the surface of the cerium oxide. A core-shell structure is formed, thereby effectively reducing the diffusion distance between the aluminum-containing compound and the cerium oxide in the subsequent solid phase reaction, and the obtained yttrium aluminum garnet powder has high purity, uniform particle size and high fluorescence intensity. At the same time, the process time of the test smectite powder is greatly shortened. According to the preferred embodiment of the present invention, the yttrium aluminum garnet (TAG) powder of the present invention and the method for producing the same have the advantages of utilizing acid aging. Step, 13 1344485, coating the aluminum-containing compound on the surface of the cerium oxide to form a core-shell structure, thereby effectively reducing the diffusion distance between the aluminum-containing compound and the cerium oxide in the subsequent solid phase reaction. Thus, the obtained yttrium aluminum The garnet powder not only has high purity, uniform particle size, high fluorescence intensity, but also greatly shortens the processing time of the yttrium aluminum garnet powder.

While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art to which the invention pertains can be made without departing from the spirit and scope of the invention. Various changes and drips 'Therefore, the scope of the invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, advantages and embodiments of the present invention will become more apparent and obvious. The detailed description of the drawings is as follows: Figure 1 (a) shows a comparative example The relationship between the surface potential of cerium oxide and the pH value;

1(b) is a diagram showing the relationship between the surface potential of the oxidized test and the soft alumina mixed slurry and the pH value according to a preferred embodiment of the present invention; and FIG. 2 is a view showing another relationship according to the present invention. An X-ray diffraction pattern of a yttrium aluminum garnet powder according to a preferred embodiment; FIG. 3 is a view showing a fluorescence spectrum of a shale stone powder according to still another preferred embodiment of the present invention; (a) is a scanning electron micrograph of cerium oxide powder without an acid aging step; and FIG. 4(b) is a scanning electron 14 1344485 microscope image of an oxidized money powder subjected to an acid aging step; 4(c) is a scanning electron micrograph of a mixed powder of cerium oxide and soft alumina without an acid aging step; and FIG. 4(d) is an oxidation test according to a further preferred embodiment of the present invention. Scanning electron micrograph of the soft alumina mixed powder; Figure 5(4) is a schematic view showing the mixed powder of cerium oxide and the inclusions without the acid aging step;

Fig. 5(8) is a schematic view showing a mixed powder of cerium and an aluminum-containing oxide according to still another preferred embodiment of the present invention.

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Claims (1)

1344485 艮b π, February 1st, down the bill, the scope of application for patents: / % Year of the month, the revised day 1 · A money name (Terbium Aluminum Garnet; TAG) powder 'the 钇 aluminum garnet powder The system is formed by a high-temperature calcination step of a core-shell structure formed by coating a surface containing an intrinsic compound on an oxidation test surface at a pH of less than or equal to 3. The chemical structure of the yttrium aluminum garnet powder is Tb3-XA15012: MX, wherein the lanthanum is selected from a group consisting of 钸, 铕, 铥, 铌, 镱, 釓, 〇$ X $ 05. 2. The yttrium aluminum garnet powder according to claim 1, wherein the aluminum compound has a chemical structural formula of A1〇〇H.yH2〇, which is A3. 3. As claimed in the patent Ιε围, the first test of the Shiquan stone powder, the temperature of the calcination step is based on the temperature of 丨4〇〇. 〇 to 丨6〇〇 It is calcined between 5 hours and 48 hours. 4. As claimed in the patent scope of claim 1, the Mingshi stone powder, wherein the illuminating wavelength of the stellite stone powder (emissi〇nwaveiength) is between 540 nm and 560 nm. 5. The method for producing a yttrium aluminum garnet powder comprises at least: oxidizing money, containing a compound, gasification enthalpy according to a chemical dose ratio of Tb(3.x)Al5〇12:Mx, The chemical structural formula of the compound is Ai〇〇H.yH2〇, which is 0$yg3 in 16 1344485; M is selected from one group consisting of lanthanum, cerium, lanthanum and sharp elements; and 0.5; undergoing acid precipitation a step of mixing the compound containing the compound, the oxidation front and the gasification bromine with 5 parts by weight of deionized water to form an acidic slurry, wherein the secret value of the acid is adjusted to be less than or equal to, Make The inclusion compound is coated on the surface of the cerium oxide to form a core-shell structure; and the high temperature calcination step is performed to calcine for a period of 5 hours to 48 hours at a temperature substantially between i4 〇 (rc to l_t: To form the (four) stone powder powder, wherein the yttrium aluminum garnet powder has an emission wavelength between 54 〇 nm and 56 〇 nm. The method for producing a yttrium aluminum garnet powder according to the fifth aspect of the invention, wherein the acid aging step adjusts the acidity and alkalinity of the acidic slurry to less than or equal to 3. 7. The method of producing a yttrium aluminum garnet powder according to claim 5, wherein the high temperature calcination step is carried out at a temperature substantially between 145 Å < t and 155 Torr. Calcining between 〇 and 24 hours to 42 hours 》 8. The method and method of yttrium aluminum garnet powder as described in claim 5, wherein after the acid aging step, it is at least included 1344485 On February 1, 2011, the replacement page drying step was modified to remove the deionized water of the acidic slurry. 18