One-step method for synthesizing leadless piezoelectric K0.1Na0.9NbO3 powder by hydrothermal process

Abstract

The invention relates to a preparation method of leadless piezoelectric ceramic K0.1Na0.9NbO3 powder, particularly a one-step method for synthesizing leadless piezoelectric K0.1Na0.9NbO3 powder by a hydrothermal process, which comprises the following steps: 1. respectively taking a 5 mol / L potassium hydroxide solution and a 5 mol / L sodium hydroxide solution, and uniformly mixing according to the KOH:NaOH mole ratio of (3-9):1 to form a mixed alkali solution xmol; 2. adding niobium pentaoxide into the mixed alkali solution according to the mixed alkali solution x:niobium pentaoxide mole ratio of (20-5):1, and magnetically stirring for 30-60 minutes to form an uniform precursor solution; carrying out hydrothermal reaction on the precursor solution at 180-220 DEG C for 6-10 hours, and cooling to room temperature to obtain a material D; and 3. flushing the material D with deionized water to a neutral state, and drying to obtain the K0.1Na0.9NbO3 powder. The method has the advantages of simple technique, favorable repetitiveness and lower requirements for reaction environment; and the prepared K0.1Na0.9NbO3 powder has the advantages of small grain size and high purity.

Description

Technical field [0001] The invention relates to a lead-free piezoelectric ceramic K 0.1 Na 0.9 NbO 3 Powder preparation method, especially a hydrothermal method for one-step synthesis of K 0.1 Na 0.9 NbO 3 Powder method. Background technique [0002] In recent years, the alkali metal niobate, namely NaNbO, which has received much attention as an electro-optical material 3 , KNbO 3 Waiting for ABO 3 Compared with lead-based piezoelectric ceramics such as PZT, the type compound has more excellent properties in all aspects, that is, low dielectric constant, high frequency constant, high piezoelectricity and low density. The development of lead-free electronic products is in line with the sustainable development trend of human society, so the research and development of lead-free piezoelectric ceramics has become a research hotspot. In addition, because metal ions such as Nb, Na, and K are non-toxic to the human body and the natural environment, and NaNbO 3 -KNbO 3 After improving th...

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Problems solved by technology

For this purpose, chemical precipitation method and sol-gel method have been reported one after another. The above methods are either complicated in operation or complex in process, long in cycle and poor in repeatability.

In contrast, the hydrothermal method has certain advantages in the synthesis of potassium sodium niobate, so it is the method adopted by most researchers; but the traditional hydrothermal method cannot avoid three problems: 1. Due to the interaction between K and Na ions and Nb The binding ability is too different. If it is synthesized by the traditional one-step hydrothermal method, (K, Na)NbO 3 The existence of K cannot be reflected in the powder at all; 2. If NaNbO is used 3 , KNbO 3 Separate synthesis and rehydration will face the problem of reasonable control of uniformity after mixing and potassium-sodium ratio after mixing, and the repeatability and accuracy of the experiment cannot be well controlled; 3. In (K, Na)NbO 3 In the process of powder preparation, the required alkaline environment is very demanding, which is not only a waste of raw materials, but also has high requirements for experimental equipment

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