Structure–property relationships of YbFe2O4– and Yb2Fe3O7–type layered oxides: A bird's eye view

Recent progress of the single crystal growth of homologous (InGaO3)m(ZnO)n

“…In contrast, for the (InGaO 3 ) m ZnO series, only m = 1 and 2 are reported. 15 This type of homologous series has also been observed in compounds of (YbFeO 3 ) m FeO, 28–30 (InGaO 3 ) m CuO, 31 and In 2 S 3 (ZnS) 1 . 32 Although the InO 6 octahedral layers in the InGaO 3 (ZnO) n system are equidistance along the c -axis, these are not seen in the (InGaO 3 ) 2 ZnO system.…”

Rational design, crystal structure, and frustrated magnetism of the Ge-containing YbFe2O4-type layered oxides In2Zn3−xCoxGeO8 (0 ≤ x ≤ 3)

“…Fe 2+/3+ ions in RFe 2 O 4 can be substituted by various combinations of divalent Cu 2+ , Co 2+ , Zn 2+ , and Mg 2+ with trivalent Ga 3+ and Al 3+ cations, forming a large family of RFe 2 O 4 -type oxides with the general chemical formula RM1 2+ M2 3+ O 4 . 7–9,21–27 These oxides show intriguing magnetic, optical, and dielectric properties. Herein, we use tetravalent Ge 4+ ions in combination with divalent M 2+ (M = Cu, Co, Zn, and Mg) ions to design a new oxide series of R 2 M 3 GeO 8 .…”

“…6 In this work, we turned our attention to another family of classic metal oxides, namely RFe 2 O 4 -type (R = Ho 3+ -Lu 3+ , Y 3+ , and In 3+ ) oxides, which adopt a hexagonal layered structure built by alternating the ∞ [RO 2 ] layer and the ∞ [FeO] 2 bilayer. 7 Intriguingly, the R 3+ and Fe 2+ /Fe 3+ cations are arranged on respective geometrically frustrated triangular nets, which can give rise to interesting magnetic behaviours, such as quantum spin liquids. 8,9 The ∞ [FeO] 2 bilayer is composed of two [FeO]-monolayers with a relative [1/3, 2/3] shift along the ab-plane, therefore producing a relatively rarely observed trigonal bipyramidal (TBP) coordination environment for Fe 2+/3+ ions.…”

“…All the above appealing physical properties have stimulated tremendous investigations on RFe 2 O 4 . Fe 2+/3+ ions in RFe 2 O 4 can be substituted by various combinations of divalent Cu 2+ , Co 2+ , Zn 2+ , and Mg 2+ with trivalent Ga 3+ and Al 3+ cations, forming a large family of RFe 2 O 4 -type oxides with the general chemical formula RM1 2+ M2 3+ O 4 [7][8][9][21][22][23][24][25][26][27]. These oxides show intriguing magnetic, optical, and dielectric properties.…”

Research Progress of ScAlMgO4 Crystal: a Novel GaN and ZnO Substrate

“…Cu、Zn 等。对于 SCAM 结构，n=m=1 [10] )。SCAM 属于六方晶系，空间群为R3 ̅ m ，晶胞参数 a=b=0.324 nm，c=2.515 nm，V=0.228 nm 3 [11][12][13][14] 。SCAM 拥有自然层状超晶格结构，其由岩盐类 [15] ，因此 SCAM 沿 c 轴方向的(0001)晶面具有很强的自然解 理特性。 [16][17][18][19] 。这 两种三角双锥体分别称为 I 型和 II 型，阳离子位于 何种三角双锥配位体取决于其从基面的位移的程度 [20] 。如图 2 所示，RAO3 结构由于其规则的三角双 金字塔几何结构，被认为具有 I 型三角双锥体结构， 而 SCAM 由于阳离子间的排斥和氧离子键的作用， 被认为具有 II 型三角双锥体结构 [11] 。其中 Al 3+ 离子 与近邻 O 2-离子之间的距离为 0.17~0.23 nm，平均距 离为 0.18 nm，Mg 2+ 离子与近邻 O 2-离子之间的距离 为 0.19~0.23 nm，平均距离为 0.20 nm [21] 。特别要 注意的是，SCAM 中 Al 3+ 离子和 Mg 2+ 离子与相邻 O 2-离子的五配位三角双锥体并未超出多组分氧化 物体系结构形成的基本原则。Walsh 等 [22][23][24][25] 的研究 工作表明，通过满足局部电荷中性的八隅规则 (Octet rule)以及材料化学计量来确定配位环境。岩 盐类结构 ScO1.5层中的八面体结构使带负电的 O 2-离 子之间最大程度上分离，对具有纤锌矿类结构 AlMgO2.5 层起到破坏堆垛层错的作用 [26][27][28][29][30] 。同时， Al 3+ 离子对八面体配位没有强烈的偏好，可以在多 种配位环境中稳定存在。因此，纤锌矿类结构层在 试图容纳 Al 3+ 离子和 Mg 2+ 离子并遵循八隅规则的同 时，必须在 AlMgO2.5 层中发生变化，从而形成五配 位三角双锥体结构 [21] 。 图 2 (RAO3)n(MO)m 族结构中两种三角双锥体的比较 [11] Fig. 2 Comparison of two types of trigonal bipyramid coordination in (RAO3)n(MO)m compounds [11] (a) Type I with D3h symmetry environment; (b) Type II with C3v symmetry environment 2 SCAM 晶体的性质 衬底的电学性能决定了后期外延和下游芯片功 能与性能的优劣 [31] [17,[33][34] 。由于金属-氧离子之间的相互作用，导致在导带与价带之间产 生带隙(禁带)。由于 SCAM 导带底部具有较大的态 密度，以及较低的能量色散，导带具有较差的电导 性能。经过屏蔽交换局域密度近似方法(Screenedexchange local-density approximation method，sX-LDA)计算得到 SCAM 电子的有效质量是 0.78me [21]…”