Effect of composition gradient on domain structure and piezoelectric properties in Mn-doped KNN single crystals

Abstract

Improvement of piezoelectric properties is always a key issue in the research of piezoelectric materials. The construction of component gradient (CG) is a novel method to improve piezoelectric properties. However,...

Large Piezoelectricity Induced by Internal Stress in (K,Na)NbO3 Single Crystals

“…According to the Bragg equation 2 d sin θ = nλ , the diffraction peak at the higher angle corresponds to 4 kinds of in-plane domains, and the one at the lower angle corresponds to 8 kinds of out-plane domains (inset of Figure a,b). The peak intensity ratio of the stronger peak to the weaker one represents the proportion of out-of-plane and in-plane domains. , The peak intensity ratio of the KNN-2 sample is 4.25, much higher than the KNN-1 sample (2.88), revealing that the out-of-plane domains are dominant in the KNN-2 sample. Furthermore, the diffraction peaks of KNN-1 sample show symmetric Gaussian distribution, indicating that the P S randomly deviated from their equilibrium position.…”

“…The peak intensity ratio of the stronger peak to the weaker one represents the proportion of out-of-plane and in-plane domains. 32,40 The peak intensity ratio of the KNN-2 sample is 4.25, much higher than the KNN-1 sample (2.88), revealing that the out-of-plane domains are dominant in the KNN-2 sample. Furthermore, the diffraction peaks of KNN-1 sample show symmetric Gaussian distribution, indicating that the P S randomly deviated from their equilibrium position.…”

“…Only after being poled, the ferroelectrics show nonzero total polarization and the piezoelectric effect is displayed. Some factors, such as strain gradient, defect dipoles, composition uniformity, etc., may influence the polarization direction distribution and domain structures, subsequently resulting in macro net self-polarization. , For example, by adjusting substrate and fabrication techniques, Pb-based ferroelectric films possess a significant self-polarization that is almost comparable to spontaneous polarization. − Additionally, in bulk ferroelectrics, some order–disorder-type organic (doped triglycine sulfate (TGS)) and perovskite ferroelectric single crystals (PMN-PSn-PT and Mn: KNN) have also been reported to display excellent self-polarization properties. − The self-polarization feature gives rise to uncommon electromechanical responses in an unpoled ferroelectric and thereby is also an effective strategy to manipulate piezoelectric performance. Therefore, a comprehensive investigation of the self-polarization and its influence on piezoelectricity and piezoelectric stability is highly demanded.…”

Processing of titanium-containing ores for the production of titanium products: A comprehensive review

“…Powdered and solid TiO 2 is recognized as a necessary ingredient in the production of white pigment. Anatase, rutile, and brookite are the three main crystal forms of TiO 2 [ [5] , [6] , [7] ]. The crystal structure of rutile TiO 2 and anatase TiO 2 is more stable than that of brookite type, and these two types of material are widely used in industrial production [ 7 ].…”

Unlocking sustainable power: advances in aqueous processing and water-soluble binders for NMC cathodes in high-voltage Li-ion batteries

“…[16][17][18] On the other hand, the removal of PVDF is difficult since it is a hydrophobic and chemically stable uorinated polymer. 16 While thermal treatment stands out as a direct method for liberating electroactive materials from PVDF, their drawbacks, including the release of hazardous products (including hydrogen uoride gas and uoride hydrocarbons such as vinylidene uoride and triuoro benzene) 19,20 and high energy consumption (500 to 700 °C pyrolysis temperature range) compromise the sustainability and economic viability of battery recycling. 18,21 Therefore, issues such as scarcity of valuable metals or groundwater and soil contamination by landll accumulation of spent LIBs can be lessened by the use of water-soluble binders.…”