Hossain K Monower, Rubel M H Kabir, Hossain M Khalid, Ishraque Toki G F, Marasamy Latha, Haldhar Rajesh, Ali Md Hasan, Baruah Smriti, A Alothman Asma, Mohammad Saikh
Department of Materials Science and Engineering, University of Rajshahi, Rajshahi 6205, Bangladesh.
Institute of Electronics, Atomic Energy Research Establishment, Bangladesh Atomic Energy Commission, Dhaka 1349, Bangladesh.
ACS Omega. 2024 Feb 19;9(8):9147-9160. doi: 10.1021/acsomega.3c08072. eCollection 2024 Feb 27.
In this study, lead-free BiM(Zn, Ca, Mg)Ti-BiFeO ceramics are fabricated under eco-friendly hydrothermal reaction conditions at 250 °C. XRD patterns show that all the synthesized compounds exhibit a phase coexistence of monoclinic and tetragonal perovskite-type structures with a morphotropic phase boundary at = 0.4, with minimum impurity. The calculated average crystallite/grain size of the samples was close to 50 nm at full width at half-maximum of the main peak. The corresponding bonds of the constituent elements were observed by FTIR analysis, which further supports the formation of the local structure. EDS analyses detect all of the elements, their quantities, and compositional homogeneity. SEM data show agglomerated and nearly spherical morphology with an average particle size of about 128 nm. All synthesized ceramic powders revealed thermal stability with trivial mass loss up to investigated high temperatures (1000 C). The dielectric constant reached its maximum at 38.7 MHz and finally remained constant after 80 MHz for all nanoceramics. Because of the complementary impact of different compositions, the most effective piezoelectric characteristics of = 136 pCN, = 8.6 pCN cm, and = 11% at 30 °C were attained at = 0.4 content for 0.4BiCaTi-0.6BiFeO ceramic. The measured magnetic hysteresis data (M-H curve) showed a weak ferromagnetic nature with the highest moment of ∼0.23 emu/g for 0.4BiCaTi-0.6BiFeO, and other samples exhibited negligible ferromagnetic to diamagnetic transition. The optical response study shows that the 0.4BiMgTi-0.6BiFeO sample yielded the maximal transmittance (50%), whereas the 0.4BiCaTi-0.6BiFeO compound exhibited the highest refractive index. The calculated large band gap shows a high insulating or dielectric nature. Our findings demonstrate that the BiMTi-BiFeO system, which was fabricated using a low-temperature hydrothermal technique, is an excellent lead-free piezoelectric and multiferroic nanoceramic.
在本研究中，无铅BiM(Zn, Ca, Mg)Ti-BiFeO陶瓷是在250°C的环保水热反应条件下制备的。X射线衍射图谱表明，所有合成化合物均呈现单斜和四方钙钛矿型结构的相共存，在 = 0.4处存在准同型相界，杂质最少。在主峰半高宽处，样品计算得到的平均微晶/晶粒尺寸接近50nm。通过傅里叶变换红外光谱分析观察到组成元素的相应键合，这进一步支持了局部结构的形成。能谱分析检测到所有元素、它们的含量以及成分均匀性。扫描电子显微镜数据显示团聚且近乎球形的形态，平均粒径约为128nm。所有合成的陶瓷粉末在高达研究的高温（1000°C）时都显示出热稳定性，质量损失很小。对于所有纳米陶瓷，介电常数在38.7MHz时达到最大值，在80MHz后最终保持恒定。由于不同成分的互补作用，在0.4BiCaTi-0.6BiFeO陶瓷中，当 = 0.4时，在30°C下获得了最有效的压电特性， = 136 pCN， = 8.6 pCN cm， = 11%。测量的磁滞数据（M-H曲线）显示出弱铁磁性质，对于0.4BiCaTi-0.6BiFeO，最高磁矩约为0.23 emu/g，其他样品表现出可忽略不计的从铁磁到抗磁转变。光学响应研究表明，0.4BiMgTi-0.6BiFeO样品的透过率最高（50%），而0.4BiCaTi-0.6BiFeO化合物的折射率最高。计算得到的大带隙显示出高绝缘或介电性质。我们的研究结果表明，采用低温水热技术制备的BiMTi-BiFeO体系是一种优异的无铅压电和多铁性纳米陶瓷。
