Lithium carbonate on the surface of garnet blocks Li + conduction and causes a huge interfacial resistance between the garnet and electrode. To solve this problem, this study presents an effective strategy to reduce significantly the interfacial resistance by replacing Li 2 CO 3 with Li ion conducting Li 3 N. Compared to the surface Li 2 CO 3 on garnet, Li 3 N is not only a good Li + conductor but also offers a good wettability with both the garnet surface and a lithium metal anode. In addition, the introduction of a Li 3 N layer not only enables a stable contact between the Li anode and garnet electrolyte but also prevents the direct reduction of garnet by Li metal over a long cycle life. As a result, a symmetric lithium cell with this Li 3 N-modified garnet exhibits an ultralow overpotential and stable plating/ stripping cyclability without lithium dendrite growth at room temperature. Moreover, an all-solid-state Li/LiFePO 4 battery with a Li 3 N-modified garnet also displays high cycling efficiency and stability over 300 cycles even at a temperature of 40 °C.

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Our experiments confirm that our method is robust and that the SPC layer helps increase the prediction accuracy. Additionally, the proposed method can easily be extended to other 3D object detection tasks in medical image processing.

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Perovskite oxides hosting ferroelectricity are particularly important materials for modern technologies. The ferroelectric transition in the well-known oxides BaTiO and PbTiO is realized by softening of a vibration mode in the cubic perovskite structure. For most perovskite oxides, octahedral-site tilting systems are developed to accommodate the bonding mismatch due to a geometric tolerance factor t = (A-O)/[√2(B-O)] < 1. In the absence of cations having lone-pair electrons, e.g., Bi and Pb, all simple and complex A-site and B-site ordered perovskite oxides with a t < 1 show a variety of tilting systems, and none of them become ferroelectric. The ferroelectric CaMnTiO oxide is, up to now, the only one that breaks this rule. It exhibits a columnar A-site ordering with a pronounced octahedral-site tilting and yet becomes ferroelectric at T ≈ 650 K. Most importantly, the ferroelectricity at T < T is caused by an order-disorder transition instead of a displacive transition; this character may be useful to overcome the critical thickness problem experienced in all proper ferroelectrics. Application of this new ferroelectric material can greatly simplify the structure of microelectronic devices. However, CaMnTiO is a high-pressure phase obtained at 7 GPa and 1200 °C, which limits its application. Here we report a new method to synthesize a gram-level sample of ferroelectric CaMnTiO, having the same crystal structure as CaMnTiO and a similarly high Curie temperature. The new finding paves the way for the mass production of this important ferroelectric oxide. We have used neutron powder diffraction to identify the origin of the peculiar ferroelectric transition in this double perovskite and to reveal the interplay between magnetic ordering and the ferroelectric displacement at low temperatures.

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"Volmer-Weber" island nucleation and step-flow growth model are the classical processes of the conventional epitaxy of films. However, a growth model of van der Waals epitaxy (vdWE) of films is still not very well-documented. Here, we present an example of vdWE of AlN films on multilayer graphene (MLG)/SiC by hydride vapor phase epitaxy at a high temperature of 1100 °C and reveal the orientation relationship of AlN, MLG, and SiC as (0001)[1-100]||(0001)[1-100]||(0001)[11-20], which suggests that the vdWE heterointerface is not an usual covalent bond and no excessive strain during the growth process owing to the incommensurate in-plane lattices. Remarkably, zigzag cracks are formed because of the anisotropy of strain after the films are cooled down to room temperature, indicating that the growth model of vdWE is different from that of conventional epitaxy. It is a layer-by-layer epitaxy, and a planar substrate without a miscut angle is essential for obtaining single-crystalline films. Additionally, the films can be transferred to foreign substrates by direct mechanical exfoliation without any stressor layer. An ultraviolet photosensor device illustrates an example of III-nitride heterogeneous integration application. Our work demonstrates an excellent step toward the vdWE of varieties of compound films on 2D materials for the applications of transferrable heterogeneous integration in future.