Hello, everyone. In this lecture, we are going to talk about another type of electride. It is built-in 2DEG, the dicalcium nitride. So we can find the material design concept for built-in 2DEG. The 2DEG is the two-dimensional electron gas. This material's design include layered structure, the spatially independent electrons from lattice atom, and appropriate inter-layer space for confinement of electrons, and simple component with stable metal valence. So we can find one important material, dicalcium nitride. Actually, the composition of dicalcium nitride is calcium 2 plus 2 and nitrogen [inaudible]. So the charge of this layer should be plus 1. So in order to make charge a neutrality, we need one electron. This like the excess electron can be confined within inter-layer space of dicalcium nitride lattice. We can fabricate the single crystal material of dicalcium nitride. So the starting material is the structure calcium nitride, and by using additional calcium, and also use the long time annealing process, we can obtain things like the single crystal material of dicalcium nitride. As shown in exile the parent, we can obtain the plate-like crystal with reflection peaks from the 00l planes. In optical characterization analysis wizard, you can find some peak near the 2.4 electron volt, which is later with the green color of this material, and also find the sharp decrease near the 1.5 electron volt, suggesting the plasma response by free carriers. The electronic transport properties of dislike to that material can be measured by stamping method as shown here. As shown in this method data, the single crystal of dicalium nitride shows metallic transport behavior. So electron-electron interaction is much stronger than that of electron-phonon interaction. Also, we can obtain the very high carrier concentration about 1.39 times 10 to the 22 per cubic centimeter. So this value is very close to the theoretical value from the three electrons per unit cell of dicalcium nitride. Also, we can obtain the high mobility about 160 centimeter square per voltage second at room temperature, and 520 centimeter square per voltage second at 2 Kelvin. So compared with other two-dimensional materials and 2DEG materials, the dicalcium nitride has higher carrier concentration and also has relatively high mobility value. So this is built-in 2DEG material which can be discovered based on the electride, can be used for many electronic devices. So measured work function value along the 00l plane and [inaudible] plane is variable. It just shows the 3.5 electron volt to the out-of-plane directions and 2.6. electron volt within the in-plane directions. So this is like low work function. The work function is the minimum energy needed to remove an electron. It's due to the loosely bound character of the conduction electrons in electrolyte. So based on this concept, we can discover so many types of electride, the such as electron dot, zero-dimensional, and electron wire, electron tube one-dimensional, and electron plate, two-dimensional electride material. And these electride cane shows the enhanced electronic, catalytic, and magnetic properties. Then recently, the new electride, the yttrium carbide having the reverted. So actually the competition of yttrium carbide is the yttrium 3 plus 2, calcium 4 minus. So this layered unit should have 2 plus charge. So in order to make charging neutrality, we need two electrons. As shown here, this is excess two electrons can be confined within interlayer spaces. So we can obtain the existence of magnetic moment preferred for the c-axis, and anisotropic magnetism from strongly localized anionic electrons with an inherent magnetic anisotropy in the interlayer spaces can be obtained as shown here. In order to come from the magnetic property generation due to the confined electrons in the electride material, the spin alignment of inter-cell atomic electron in 2D interlayer can be tuned by chemical pressure. So it makes by scandium substitution on the yttrium site. So this is like widet that indicates that we can control the magnetic property of 2D electrons by lattice engineering. This is like the concept of electride can provide us new material publication technology which is the later is with the changing over of [inaudible] of material. So as shown here, dimensional manipulation of a crystal structure can provide us the discovery of a new two-dimensional materials. So we can fabricate the layered structure of Zintl phase to which constructed by the stacking of SP2 hybridized honeycomb ZnSb layers from the SP3 hydrolyzed 3D ZnSb phase. Also, the concept of electride can be used for the publication of ultrafine oxide particle. As you know, the current, the oxide, the manipulation technique contains the intrinsic control such as compositional and crystal structure tuning, and extrinsic control such as size, dimension, reduction and facet, lattice engineering, hetero structuring, and compositional, and defect engineering. If you use the cation implantation, so we can realize that the several types, new type of ceramic material with deformed structure and the defect structure, and we can induce the phase transition, and also makes the downsized material, and finally, we can fabricates the amorphized ceramic material. So this is like the cation implantation that provides us with some newly described defect engineering structuring techniques. So it generates the dislike grain boundary, the structure, and oxygen vacancy structure, especially at the surface of oxygen oxide particles. Then finally, it generates nanopores, and then we can obtain the very small size oxide particle. So as we discussed, this is like electrified concept can provide a lot of material engineering approaches to develop the novel functional ceramics. Thank you.
