Rettenwander D, Geiger C A, Tribus M, Tropper P, Wagner R, Tippelt G, Lottermoser W, Amthauer G
Department of Materials Research and Physics, University of Salzburg, 5020 Salzburg, Austria.
Institute of Mineralogy and Petrography, Faculty of Geo- and Atmospheric Sciences, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria.
J Solid State Chem. 2015 Oct;230:266-271. doi: 10.1016/j.jssc.2015.01.016.
A series of Fe-bearing LiLaZrO (LLZO) garnets was synthesized using solid-state synthesis methods. The synthetic products were characterized compositionally using electron microprobe analysis and inductively coupled plasma optical emission spectroscopy (ICP-OES) and structurally using X-ray powder diffraction and Fe Mössbauer spectroscopy. A maximum of about 0.25 Fe pfu could be incorporated in Li Fe LaZrO garnet solid solutions. At Fe concentrations lower than about 0.16 pfu, both tetragonal and cubic garnets were obtained in the synthesis experiments. X-ray powder diffraction analysis showed only a garnet phase for syntheses with starting materials having intended Fe contents lower than 0.52 Fe pfu. Back-scattered electron images made with an electron microprobe also showed no phase other than garnet for these compositions. The lattice parameter, , for all solid-solution garnets is similar with a value of ≈12.98 Å regardless of the amount of Fe. Fe Mössbauer spectroscopic measurements indicate the presence of poorly- or nano-crystalline FeLaO in syntheses with Fe contents greater than 0.16 Fe pfu. The composition of different phase pure Li Fe LaZrO garnets, as determined by electron microprobe (Fe, La, Zr) and ICP-OES (Li) measurements, give LiFeLaZrO, LiFeLaZrO, LiFeLaZrO, and LiFeLaZrO. The Fe Mössbauer spectrum of cubic LiFeLaZrO garnet indicates that most Fe occurs at the special crystallographic 24 position, which is the standard tetrahedrally coordinated site in garnet. Fe in smaller amounts occurs at a general 96 site, which is only present for certain Li-oxide garnets, and in LiFeLaZrO this Fe has a distorted 4-fold coordination.
采用固态合成方法合成了一系列含铁的LiLaZrO（LLZO）石榴石。使用电子微探针分析和电感耦合等离子体发射光谱法（ICP - OES）对合成产物进行成分表征，并使用X射线粉末衍射和Fe穆斯堡尔光谱进行结构表征。在LiFeLaZrO石榴石固溶体中最多可掺入约0.25 Fe pfu（每化学式单位）。在Fe浓度低于约0.16 pfu时，合成实验中得到了四方和立方石榴石。X射线粉末衍射分析表明，对于起始原料中预期Fe含量低于0.52 Fe pfu的合成，仅出现石榴石相。用电子微探针制作的背散射电子图像也表明，对于这些成分，除石榴石外没有其他相。所有固溶体石榴石的晶格参数a≈12.98 Å，与Fe含量无关。Fe穆斯堡尔光谱测量表明，在Fe含量大于0.16 Fe pfu的合成中存在微晶或纳米晶的FeLaO。通过电子微探针（Fe、La、Zr）和ICP - OES（Li）测量确定的不同相纯LiFeLaZrO石榴石的成分分别为LiFeLaZrO、LiFeLaZrO、LiFeLaZrO和LiFeLaZrO。立方LiFeLaZrO石榴石的Fe穆斯堡尔光谱表明，大多数Fe出现在特殊的晶体学24位置，这是石榴石中标准的四面体配位位置。少量的Fe出现在一般的96位置，该位置仅在某些锂氧化物石榴石中存在，在LiFeLaZrO中，这种Fe具有扭曲的四重配位。
