Prywer Jolanta, Kruszyński Rafał, Świątkowski Marcin, Soszyński Andrzej, Kajewski Dariusz, Roleder Krystian
Institute of Physics, Lodz University of Technology, ul. Wólczańska 219, 90-924, Łódź, Poland.
Institute of General and Ecological Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924, Łódź, Poland.
Sci Rep. 2021 Jul 21;11(1):14860. doi: 10.1038/s41598-021-94410-2.
In this paper, we present the first experimental evidence of the piezoelectric nature of struvite (MgNHPO·6HO). Using a single diffusion gel growth technique, we have grown struvite crystals in the form of plane parallel plates. For struvite crystals of this shape, we measured the piezoelectric coefficients d and d. We have found that at room temperature the value of piezoelectric coefficient d is 3.5 pm/V, while that of d is 4.7 pm/V. These values are comparable with the values for other minerals. Struvite shows stable piezoelectric properties up to the temperature slightly above 350 K, for the heating rate of 0.4 K/min. For this heating rate, and above this temperature, the thermal decomposition of struvite begins, which, consequently, leads to its transformation into dittmarite with the same non-centrosymmetric symmetry as in case of struvite. The struvite-dittmarite transformation temperature is dependent on the heating rate. The higher the heating rate, the higher the temperature of this transformation. We have also shown that dittmarite, like struvite exhibits piezoelectric properties.
在本文中，我们展示了鸟粪石（MgNH₄PO₄·6H₂O）压电性质的首个实验证据。使用单扩散凝胶生长技术，我们生长出了平行平板状的鸟粪石晶体。对于这种形状的鸟粪石晶体，我们测量了压电系数d₃₁和d₃₃。我们发现，在室温下，压电系数d₃₁的值为3.5皮米/伏，而d₃₃的值为4.7皮米/伏。这些值与其他矿物的值相当。对于0.4开尔文/分钟的升温速率，鸟粪石在略高于350 K的温度下仍表现出稳定的压电性能。在此升温速率及高于此温度时，鸟粪石开始热分解，进而导致其转变为迪特马石，其具有与鸟粪石相同的非中心对称对称性。鸟粪石 - 迪特马石的转变温度取决于升温速率。升温速率越高，该转变的温度越高。我们还表明，迪特马石与鸟粪石一样具有压电性能。
