CN103833228B - Chromium ion-doped devitrified glass of a kind of tetravalence and preparation method thereof - Google Patents

Abstract

Devitrified glass disclosed by the invention comprises glass basis and chromium-doped ion, wherein glass basis component and mass percentage content as follows: SiO ₂43.5%, Al ₂o ₃16%, ZnO? 19.6%, MgO? 0.5%, Li ₂o? 7.5%, K ₂o? 12.9%, the mass percent of chromium-doped ion is 0.01 ~ 1.5% of glass basis component, and the chemical formula of devitrified glass is Li _1.14zn _1.43-xmg _xsiO ₄, 0.01 & lt; X? & lt; 0.1.Its preparation method comprises: first adopt two step glass meltings, obtains chromium doped-glass matrix; Then adopt two step devitrified glass thermal treatment process, obtain the chromium ion-doped devitrified glass of tetravalence.Present invention achieves crystallite lattice ion in devitrified glass to replace, improve the performance of devitrified glass.

Description

A kind of tetravalent chromium ion doped glass ceramics and preparation method thereof

technical field

The invention relates to a glass-ceramic, in particular to a tetravalent chromium ion-doped glass-ceramic and a preparation method thereof, belonging to the technical field of material science.

Background technique

Glass-ceramic refers to a class of composite materials in which nanocrystals are distributed in a continuous glass phase. The preparation method is usually to first prepare a matrix glass with designed components, and then heat-treat the prepared matrix glass at a certain temperature to precipitate nanocrystals in situ, that is, to obtain a glass-ceramic. Glass-ceramics also has the characteristics of stable physical and chemical properties of glass, high mechanical strength, and easy processing, and has the characteristics of low phonon energy in crystals, which can reduce the non-radiative transition probability of doped luminescent ions and improve its quantum efficiency and luminous efficiency. . Therefore, it has good application prospects in the fields of solid-state lasers, optical communications and optical information.

Nanocrystals in glass-ceramics generally belong to ionic crystals. According to Pauling's rules, the structural arrangement of ionic crystals mainly depends on the ionic radius and coordination number, so ions with similar ionic radii and coordination numbers are easy to interact with each other. substitution without changing the structure of the ionic crystal itself. In the study of crystal materials, there have been many studies on ion substitution to improve the performance of ceramic materials. For example, Zheng Changwei studied that Mg was replaced by Zn substitution in MgAl ₂ O ₄ to obtain Mg _1-x Zn _x Al ₂ O ₄ materials, which significantly improved Dielectric properties such as the dielectric constant and quality factor of the material; while Zhang Shuren studied the replacement of Mg by Zn in MgTiO ₃ ceramics to obtain Mg _1-x Zn _x TiO ₃ materials, which improved the sintering performance of the material and reduced its sintering performance. temperature.

It is found that in crystal materials, two ions with similar ionic radius and coordination number can realize the mutual substitution between ions through appropriate preparation process. However, although ion substitution in crystalline materials has been realized for a long time, so far there has been no research on the substitution of ions between crystallites in glass-ceramics.

Contents of the invention

The purpose of the present invention is to improve the performance of glass ceramics, provide a tetravalent chromium ion doped glass ceramics in which the Zn ²⁺ part of the crystal lattice ions in the glass ceramics is replaced by Mg ²⁺ and a preparation method thereof.

The tetravalent chromium ion-doped glass-ceramics of the present invention includes matrix glass and doped chromium ions, wherein the glass matrix components and mass percent content are as follows:

SiO ₂ 43.5%

Al ₂ O ₃ 16%

ZnO 19.6%

MgO 0.5%

_Li2O 7.5%

K ₂ O 12.9%

Doped chromium ions are introduced in the form of Cr ₂ O ₃ , and its mass percentage is 0.01~1.5% of the glass matrix components,

The chemical formula of glass ceramics is Li _1.14 Zn _1.43-x Mg _x SiO ₄ , 0.01< x <0.1.

The preparation method of tetravalent chromium ion-doped glass ceramics of the present invention, the steps are as follows:

1) Weigh 43.5% of SiO ₂ , 16% of Al ₂ O ₃ , 19.6% of ZnO, 0.5% of MgO, 7.5% of Li ₂ O, 12.9% of K ₂ O, and add the above total amount 0.01~1.5% Cr ₂ O ₃ ; mix the above components evenly, keep the temperature at 1500~1600 ℃ for 30~60 minutes, then reduce the melting temperature to 1300~1400 ℃ and keep it for 10~30 minutes, pour the molten liquid Put it into a preheated iron mold, heat it at 500°C for 1 hour and anneal it, then cool it down to room temperature naturally to get a chromium-doped glass matrix;

2) Heat the chromium-doped glass substrate prepared in step 1) at 625-675 °C for 12-24 hours for heat treatment, then raise the temperature to 700-800 °C for 1-4 hours, then cool down to room temperature naturally to obtain tetravalent chromium ions Doped glass-ceramic.

The preparation of the tetravalent chromium ion-doped glass-ceramic of the present invention includes glass melting process and glass-ceramic heat treatment process. In the glass melting process, a two-step melting method is adopted. Firstly, heat preservation is carried out at a relatively high melting temperature (1500~1600 ℃) to improve the fluidity of the glass melt, so as to achieve full and uniform raw materials of each component. The purpose of mixing is to create a consistent environment for the substitution of microcrystalline lattice ions in the subsequent heat treatment, and then reduce the melting temperature (1300~1400°C), increase the viscosity of the glass melt, reduce the fluidity of the glass melt, and make the glass more convenient forming.

In the heat treatment process of glass-ceramics, a two-step heat treatment method is adopted. First, the temperature is lower than the glass crystallization start temperature (625~675 ℃) for a long time. At this temperature, the crystallites are metastable between amorphous and crystalline states state, the activity is relatively high, which is conducive to the substitution reaction between ions with similar ionic radii and ligands, and long-term heat preservation will not cause excessive growth of the crystallites, resulting in the crystallized glass-ceramics becoming opaque, and then increasing the heat treatment temperature To the crystallization temperature range of microcrystals (700~800 ℃), microcrystals are precipitated.

The present invention prepares tetravalent chromium ion-doped glass-ceramic Li _1.14 Zn _1.43-x Mg _x SiO ₄ by optimizing the glass melting process and glass-ceramic heat treatment process, 0.01<x<0.1, realizing the glass-ceramics Substitution of ions in the microcrystalline lattice improves the properties of the glass-ceramics.

Description of drawings:

Fig. 1 is the XRD collection of illustrative plates of embodiment 1 glass-ceramics;

Fig. 2 is the fluorescence spectrogram of the glass-ceramic of embodiment 1.

Detailed ways

The present invention will be further described below in conjunction with specific examples.

Example 1:

According to the base glass composition 43.5SiO ₂ -16Al ₂ O ₃ -20.1ZnO-7.5Li ₂ O-12.9K ₂ O (mass percentage), the Cr ₂ O ₃ doping concentration is 0.1% (mass percentage) of the base glass, respectively Weigh, 43.5 g of SiO ₂ , 16 g of Al ₂ O ₃ , 19.6 g of ZnO, 0.5 g of MgO, 7.5 g of Li ₂ O, 12.9 g of K ₂ O and 0.1 g of Cr ₂ O ₃ , the The above components are mixed evenly. First, keep the temperature at 1550 °C for 40 minutes, then reduce the melting temperature to 1350 °C and keep it for 30 minutes. Then cool down to room temperature naturally, and take out to obtain the chromium-doped glass matrix;

The above-mentioned chromium-doped glass substrate is first heat-treated at 650°C for 18 hours, then raised to 720°C for 2 hours, and then naturally lowered to room temperature to obtain the tetravalent chromium ion-doped glass-ceramics of the present invention. .

The XRD test results of the glass-ceramic are shown in Figure 1. It can be seen from the figure that the diffraction peaks of the crystallite crystal phase completely correspond to the Li _1.14 Zn _1.43 SiO ₄ crystal phase in the JCPDS standard card, but there is a 0.8° difference in the 2θ angle. Shifting to the right indicates that although the lattice structure has not changed in the microcrystal, the lattice ions may have changed, indicating that some Zn ²⁺ ions in the Li _1.14 Zn _1.43 SiO ₄ microcrystal are replaced by Mg ²⁺ ions.

The test results of the fluorescence spectrum of the glass-ceramics are shown in Figure 2. It can be seen from the figure that the emission center of the glass-ceramics is 1268 nm, and the half-maximum width of the emission spectrum is 280 nm. Compared with tetravalent chromium ions doped with Li _1.14 Zn _1.43 SiO ₄ glass-ceramics, the emission center of the glass-ceramics has been red-shifted, and the half-maximum width of the emission spectrum has become wider.

Example 2:

According to the base glass composition 43.5SiO ₂ -16Al ₂ O ₃ -20.1ZnO-7.5Li ₂ O-12.9K ₂ O (mass percentage), the Cr ₂ O ₃ doping concentration is 0.5% (mass percentage) of the base glass, respectively Weigh, 43.5 g of SiO ₂ , 16 g of Al ₂ O ₃ , 19.6 g of ZnO, 0.5 g of MgO, 7.5 g of Li ₂ O, 12.9 g of K ₂ O and 0.5 g of Cr ₂ O ₃ , put The above components are mixed evenly. First, keep the temperature at 1600°C for 30 minutes, then lower the melting temperature to 1300°C and keep it for 10 minutes. Then cool down to room temperature naturally, and take out the chromium-doped glass substrate;

The above-mentioned chromium-doped glass substrate is firstly heat-treated at 625°C for 24 hours, then raised to 800°C for 1 hour, and then naturally lowered to room temperature to obtain the tetravalent chromium ion-doped glass-ceramic of the present invention. .

The XRD test results show that the crystallites in the glass-ceramics are Li _1.14 Zn _1.43 SiO ₄ crystal phase, and the diffraction peaks shift to the right by 0.7°, indicating that although the lattice structure does not change in the crystallites, lattice ions may occur The changes showed that part of the Zn ²⁺ ions in the Li _1.14 Zn _1.43 SiO ₄ crystallites were replaced by Mg ²⁺ ions.

The results of the fluorescence spectrum test show that the emission center of the glass _- ceramic is _{1265 nm} , and the half-maximum width of the emission spectrum is 285 nm. A red shift occurs, and the half-maximum width of the emission spectrum becomes wider.

Example 3:

According to the base glass composition 43.5SiO ₂ -16Al ₂ O ₃ -20.1ZnO-7.5Li ₂ O-12.9K ₂ O (mass percentage), the doping concentration of Cr ₂ O ₃ is 1.5% (mass percentage) of the base glass, respectively Weigh, 43.5 g of SiO ₂ , 16 g of Al ₂ O ₃ , 19.6 g of ZnO, 0.5 g of MgO, 7.5 g of Li ₂ O, 12.9 g of K ₂ O and 1.5 g of Cr ₂ O ₃ , put The above components are mixed evenly. First, heat preservation at 1500 °C for 60 minutes, then reduce the melting temperature to 1400 °C and heat preservation for 30 minutes, pour the molten liquid into a preheated iron mold, and heat at 500 °C for 1 hour for annealing Then cool down to room temperature naturally, and take out to obtain the chromium-doped glass matrix;

The above-mentioned chromium-doped glass substrate is first heat-treated at 675°C for 12 hours, then raised to 700°C for 4 hours, and then naturally lowered to room temperature to obtain the tetravalent chromium ion-doped glass-ceramics of the present invention. .

The XRD test results show that the crystallites in the glass-ceramics are Li _1.14 Zn _1.43 SiO ₄ crystal phase, and the diffraction peaks shift to the right by 0.85°, indicating that although the lattice structure does not change in the crystallites, lattice ions may occur The changes showed that part of the Zn ²⁺ ions in the Li _1.14 Zn _1.43 SiO ₄ crystallites were replaced by Mg ²⁺ ions.

The results of the fluorescence spectrum test show that the emission center of the glass _- ceramic is _{1270 nm} , and the half-maximum width of the emission spectrum is 290 nm. A red shift occurs, and the half-maximum width of the emission spectrum becomes wider.

Claims (2)

1. A tetravalent chromium ion-doped glass-ceramic, characterized in that the glass-ceramic comprises a glass matrix and doped chromium ions, wherein the glass matrix components and mass percent content are as follows: SiO ₂ 43.5% Al ₂ O ₃ 16% ZnO 19.6% MgO 0.5% _Li2O 7.5% K ₂ O 12.9% Doped chromium ions are introduced in the form of Cr ₂ O ₃ , and its mass percentage is 0.01~1.5% of the glass matrix components, The chemical formula of glass ceramics is Li _1.14 Zn _1.43-x Mg _x SiO ₄ , 0.01< x <0.1. 2. prepare the method for tetravalent chromium ion doped glass ceramics as claimed in claim 1, the steps are as follows: 1) Weigh 43.5% of SiO ₂ , 16% of Al ₂ O ₃ , 19.6% of ZnO, 0.5% of MgO, 7.5% of Li ₂ O, 12.9% of K ₂ O, and add the above components The total amount of Cr ₂ O ₃ is 0.01~1.5%; mix the above components evenly, keep the temperature at 1500~1600 ℃ for 30~60 minutes, then reduce the melting temperature to 1300~1400 ℃ for 10~30 minutes, melt the Pour the solution into the preheated iron mold, heat it at 500 ℃ for 1 hour and anneal, then cool it down to room temperature naturally to obtain a chromium-doped glass matrix; 2) Heat the chromium-doped glass substrate prepared in step 1) at 625-675 °C for 12-24 hours for heat treatment, then raise the temperature to 700-800 °C for 1-4 hours, then cool down to room temperature naturally to obtain tetravalent chromium ions Doped glass-ceramic.