最後に、これまでに報告されたa-TaONの合成例について取り上げる。現

最後に、これまでに報告されたa-TaONの合成例について取り上げる。現在確認されている合成例はたったの2例のみである。この2例の合成方法だが、いずれもアンモノリシス法という酸化物前駆体を高温下でアンモニアによって部分窒化させる方法をとっている[1.15,1.16]。アンモノリシス法の簡単な模式図をFig.1-1-9に示した。合成の制約としては、出発物質に粉末多結晶体を使用するため、生成物もまた粉末多結晶体に限られる点やアンモニアと反応させるため800度以上の高温が必要とされる点があげられる。またこれらの論文では、酸化物前駆体にはTa2O5そのものではなく、MgやScを5-15%程度ドープしたものを使用している。これには不純物ドープにより準安定構造であるアナターゼ構造を安定化する役割がある。Mgを5%ドープしたa-TaONの吸収スペクトルをFig. 1-1-10に示した。b-TaONと同様に可視光域に吸収を持つことがわかる。また、格子定数やScドープのa-TaONの結果について表1-1-2にまとめた。これらのアナターゼ型TaONはバデライト型よりも小さなEgを持つという表1-1-1の理論計算と同様な結果を示している。また、格子定数についても理論計算とよくマッチしているという結果が示された。a-TaONの物性報告例は現在のところ、このバンドギャップの大きさのみである。この点もやはり、酸窒化物一般にいえる物性報告例の乏しさ

結果 (英語) 1:

Discuss the synthesis of a-TaON reported at the end. Only synthetic cases have now been confirmed in only two cases. Synthesis method for these two examples, but any oxide precursor called ammonolithis under high temperature by ammonia part nitriding method of [1.15, 1.16]. Fig.1-1-9 shows a simple schematic diagram of the ammonolithis method. Given the limited artifacts are also on polycrystalline powder for polycrystalline powder starting material to use as a constraint for the synthesis and the high temperatures of 800 degrees or more is needed to react with ammonia and points. Using doped Mg and Sc 5-15 percent, rather than in those papers, the precursor of oxide Ta2O5 itself also. There is this metastable structures by the impurity-doped anatase structure stabilization role. A-TaON 5% mg-doped Spectra Fig... Shown 1-1-10. similar to b-TaON with absorption in the visible light region is understood. Also a-TaON Sc-doped and lattice constant results summarized in table 1-1-2. The anatase TaON these than bad light has shown similar to having a small Eg table 1-1-1 theoretical results. The indicated results that are well-matched with theoretical calculations on the lattice constant. a-TaON properties of reported cases is at present only the size of the band gap. This point also of scarcity of properties reported cases still be generally acid nitride

結果 (英語) 2:

Finally, we take up for the synthesis example of a-TaON that have been reported so far. Synthesis example that is currently confirmed only just two examples. Although it is the synthesis method of the two cases are taking a way to partially nitride, by ammonia oxide precursor under a high temperature of both ammonolysis method [1.15,1.16]. A simple schematic diagram of the ammonolysis method I have shown in Fig.1-1-9. Synthetic constraints for the use of powdered polycrystalline starting material, the product is also a point to be powdered polycrystalline body is limited by a point or ammonia and require 800 degrees or more of the high temperature to react the like . In these papers, not Ta2O5 itself the oxide precursor is being used after Mg and Sc to about 5-15% dope. This has the role to stabilize the anatase structure is metastable structure by impurity doping. The absorption spectrum of a-TaON that the Mg 5% dope I was shown in Fig. 1-1-10. b-TaON and it is found to have absorbed similarly to the visible light region. Also, we summarized in Table 1-1-2 for the results of a-TaON of lattice constant and Sc-doped. These anatase TaON shows similar results and theoretical calculation of Table 1-1-1 of having a small Eg than baddeleyite type. In addition, as a result of being matched well with the theoretical calculation also lattice constant has been shown. physical properties reported cases of a-TaON currently, is only the size of the band gap. This point Again, poor physical properties reported cases that say to oxynitride general

結果 (英語) 3:

Finally, a synthesis of TaON cases reported so far. The case is currently known only in only 2 cases. Two cases of this synthesis method, and how to 1.15 oxide precursor called ammonolysis process and by nitridation in ammonia under high temperature is,'s 1.16 A simple method of ammonolysis Fig schematic diagram shown in 1 case. As a constraint for the use of polycrystalline powder in the starting materialProducts for the reaction of ammonia and only polycrystalline powder may be that more than 800 degree and high temperature is required. Moreover, the oxide precursor Ta 2 5 O itself, not to Mg and Sc used about 5-15% doped. This role is to stabilize the anatase structure doped with impurities in metastable structure. To Fig absorption spectra of doped TaON 5 shown in Mg 1-1.It is understood that in the visible region absorption as well as for TaON. In addition, the lattice constant of Sc dope and a TaON results are summarized in Table 1. These TaON anatase type is similar to the case of theoretical calculation with small Eg バデライト than results. In addition, the lattice constants and the result is well matched with the theoretical calculation is shown. At present a case report of TaON properties, only to the size of the band gap. This also,It can be said that in the case of poor general oxynitride