Nd(Mg_(1/2)Sn_(1/2))O_3(NMS)ceramic was synthesized using a conventional solid-state reaction method.Crystal structure and morphology were investigated through X-ray diffraction(XRD)and scanning electron micrograph(SE...Nd(Mg_(1/2)Sn_(1/2))O_3(NMS)ceramic was synthesized using a conventional solid-state reaction method.Crystal structure and morphology were investigated through X-ray diffraction(XRD)and scanning electron micrograph(SEM)technologies,respectively.Lattice vibrational modes展开更多
Non-stoichiometric Nd_((1+x))(Mg_(1/2)Sn_(1/2))O_(3)(-0.04=x≤0.04,NMS)ceramics were fabricated via a conventional solid-state reaction method.Crystal structures and morphologies were investigated by Xray diffraction(...Non-stoichiometric Nd_((1+x))(Mg_(1/2)Sn_(1/2))O_(3)(-0.04=x≤0.04,NMS)ceramics were fabricated via a conventional solid-state reaction method.Crystal structures and morphologies were investigated by Xray diffraction(XRD)and scanning electron microscopy(SEM),respectively.The main crystalline phase is monoclinic Nd(Mg_(1/2)Sn_(1/2))O_(3) with a double perovskite structure(P21/n space group)for the NMS system proved by XRD.The sample at x=0.01 has the best crystallinity and evenly distributed crystal grains observed by SEM.The optimum performances(ε_(r)=19.87,Q×f=41840 GHz,f=12.05 GHz)are obtained at x=0.01.Lattice vibrational modes of the Raman spectra were assigned and illustrated,in detail.The dielectric properties obtained by fitting infrared reflectance spectra with the help of four-parameter semi-quantum model are consistent with the calculated values by microscopic polarization and damping coefficients.The reverse translational vibration of the NdeMgO_(6),the F_(5u)^((5)) mode,provides the greatest contribution to the dielectric response.The relationships between crystal structures and dielectric properties were mainly established using lattice vibrational modes as a media.展开更多
BaMoO_(4)ceramic was prepared using a conventional solid-sintering method.It was observed that the sample is a pure BaMoO_(4)with a tetragonal scheelite structure by analyzing X-ray diffraction data.Scanning electron ...BaMoO_(4)ceramic was prepared using a conventional solid-sintering method.It was observed that the sample is a pure BaMoO_(4)with a tetragonal scheelite structure by analyzing X-ray diffraction data.Scanning electron microscopy characterized the dense sample with uniform grains.The phonon modes were analyzed by Raman and Far-infrared reflection spectra,and the phonon characteristics were studied.The intrinsic properties of the sample were calculated by the four-parameter semi-quantum model as well as the Clausius-Mosotti&damping equations,and the results were ofεr=9.388 and tanδ=4.760×10^(-4),εr=9.798 and tanδ=6.445×10^(-4),respectively,which agrees well with the experimental values(εr=9.84,tanδ=5.0×10^(-4)).The contributions to dielectric properties of each mode were investigated,and the results indicate that the external mode(Eu)yield greatest contribution to intrinsic permittivity and loss.展开更多
文摘Nd(Mg_(1/2)Sn_(1/2))O_3(NMS)ceramic was synthesized using a conventional solid-state reaction method.Crystal structure and morphology were investigated through X-ray diffraction(XRD)and scanning electron micrograph(SEM)technologies,respectively.Lattice vibrational modes
基金supported by National Natural Science Foundation of China(Grant 11874240)Guangxi Information Materials Key Laboratory Open Research Fund(171007-K)+3 种基金State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KF201811)the Opening Project of Key Laboratory of Inorganic Functional Materials and Devices,Chinese Academy of Sciences(Grant No.KLIFMD201803)the Natural Science Foundation of Shandong Province,China(No.ZR2016EMM21)Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(No.2016RCJJ002).
文摘Non-stoichiometric Nd_((1+x))(Mg_(1/2)Sn_(1/2))O_(3)(-0.04=x≤0.04,NMS)ceramics were fabricated via a conventional solid-state reaction method.Crystal structures and morphologies were investigated by Xray diffraction(XRD)and scanning electron microscopy(SEM),respectively.The main crystalline phase is monoclinic Nd(Mg_(1/2)Sn_(1/2))O_(3) with a double perovskite structure(P21/n space group)for the NMS system proved by XRD.The sample at x=0.01 has the best crystallinity and evenly distributed crystal grains observed by SEM.The optimum performances(ε_(r)=19.87,Q×f=41840 GHz,f=12.05 GHz)are obtained at x=0.01.Lattice vibrational modes of the Raman spectra were assigned and illustrated,in detail.The dielectric properties obtained by fitting infrared reflectance spectra with the help of four-parameter semi-quantum model are consistent with the calculated values by microscopic polarization and damping coefficients.The reverse translational vibration of the NdeMgO_(6),the F_(5u)^((5)) mode,provides the greatest contribution to the dielectric response.The relationships between crystal structures and dielectric properties were mainly established using lattice vibrational modes as a media.
基金National Natural Science Foundation of China(Grant 11874240)the Taishan Scholarship Project of Shandong Province,China(No.tshw20130956)+3 种基金the Natural Science Foundation of Shandong Province,China(No.ZR2016EMM21)Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(No.2016RCJJ002)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(No.SKL201503SIC)the State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KF201811).
文摘BaMoO_(4)ceramic was prepared using a conventional solid-sintering method.It was observed that the sample is a pure BaMoO_(4)with a tetragonal scheelite structure by analyzing X-ray diffraction data.Scanning electron microscopy characterized the dense sample with uniform grains.The phonon modes were analyzed by Raman and Far-infrared reflection spectra,and the phonon characteristics were studied.The intrinsic properties of the sample were calculated by the four-parameter semi-quantum model as well as the Clausius-Mosotti&damping equations,and the results were ofεr=9.388 and tanδ=4.760×10^(-4),εr=9.798 and tanδ=6.445×10^(-4),respectively,which agrees well with the experimental values(εr=9.84,tanδ=5.0×10^(-4)).The contributions to dielectric properties of each mode were investigated,and the results indicate that the external mode(Eu)yield greatest contribution to intrinsic permittivity and loss.
