薄板状の高誘電率材料を得ることを目的とした, BaOおよびTiO₂を多量に含むガラスの結晶化に関する研究はすでに二, 三報告されている. しかし, 実際に薄板状の結晶化ガラスを作り, その誘電的性質について調べた結果はまだ報告されていない. 本研究では, BaO・TiO₂-Al₂O₃-SiO₂系のガラスについて, 厚さ100μ以下の薄板状結晶化ガラスを作る方法を検討し, また得られた結晶化ガラスの誘電的性質および微細構造などについて調べた.
得られた結果は次の通りである.
1. ガラス融液の入った坩堝を, 底に穴をあけた炉内で逆転し, 炉の下に流れ落ちる融液を相接する鉄製ローラーの間を通して成形することにより, 50-100μ厚の薄板状ガラスを作ることができた. また同ガラスを再加熱することにより, 亀裂やしわのない, 機械的にもかなり強い結晶化物を得ることができた.
2. 薄板状結晶化ガラスの誘電率はガラス組成中のBaO・TiO₂含有量が多いほど大きく, またBaO・TiO₂含有量が一定の時には, Al₂O₃とSiO₂の比が約35/65 (モル比) 付近で最大となった. この実験で誘電率の最高が475, そのtan δが300×10^-4 (周波数1Mc) のものが得られた.
3. これらの結晶化ガラスの誘電率は試料の厚さが薄くなるに従い小さくなり, 特に約200μ以下の厚さの時には急に小さくなることを見出した. 結晶化ガラスの微細構造を調べた結果, 試料の厚さによる誘電率の変化は, 試料表面付近のヘキサセルシアンの配向が大きな原因となっていると考えられた.

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There have been very extensive studies on the photochemistry of transition elements in various glasses by many authors, but very few, of non-metallic anions dissolved in glasses. Therefore, the photochemistry of NaI containing sodiumsilicate glasses was investigated by the writers. The reason the writers took NaI as the reagent was that the photochemistry of iodine in some solvents and it's electronic state had been fairly well known. The samples used in this study are shown in Table 1. The increases of absorption spectra after X-and UV irradiation, photo and thermal fading of their induced absorption were studied.
The increases of optical absorption in UV or X-ray irradiated glasses are shown in Fig. 1 and 2. Fig. 3 shows, how the induced absorption in the same glass after UV irradiation is affected by water.
Photo and thermal fading of these induced absorption bands are shown in Fig. 4-8.
As the result of examining of such absorption changes, it became clear that the induced absorption bands after X-or UV irradiation were 250-270mμ, 290mμ, 350mμ, 380mμ, and 715mμ and in the case of dilute NaI containing glasses, moreover some weakend color centers of sodium silicate glasses in itself were overlapped on these induced bands, namely, iodine ion has a suppression effect on the growth of glass color centers by X-ray or UV irradiation.
Conversely 570mμ band (electron trapping center in reduced Na₂O-3SiO₂ glass) was strengthened by photochemistry of NaT as shown in Fig. 12, but was very unstable.
Considering on the above results, the photochemistry of NaI containing glass is the photo-oxidation of I^- in the glass.
Assignments of induced bands after the irradiation are as follows; 250-270mμ band depends on a electron trapping center in glass matrix, 290, 350mμ and 380, 715mμ depend upon I₃^- and I₂^- respectively.
The more basic is the glass, the absorptions of I₃^- and I₂^- are the more unstable, and moreover they causes thermal fading at the lower temperature.

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Glass samples containing various compositions in fairly wide range were prepared by melting raw materials consisting of elementary As and S in definite proportions in sealed vacuum tube.
The method of chemical analysis of these glasses was examined (Table 3). As was determined by the modified Volhard method, the iodometric method and the gravimetric method. In the last case, As was oxidised to As₂O₅ by use of fuming HNO₃. S was determined by the gravimetric method as BaSO₄, after S was converted to SO₄ ion.
Molecular volume, molecular refraction (Table 4 and Fig. 1), hardness (Fig. 2) and viscosity (Fig. 3, 4) of these glasses were investigated and, additionally, solubility ofthese glasses to CS₂ was measured (Fig. 5, 6). It has been recognized that S of ring form type dissolves easily to CS₂, but the case is not in S of chain like type.
The results obtained are as follows.
(1) No As=S bond seems to exist in these glasses.
(2) The As-As bond must exist in the glasses which have lower content of sulfur than that of As₂S₃.
(3) with increasing S content over As₂S₃, S is likely to exist as chain like form type but in such range that the content of S is over that of As₂S_8-10, some parts of S are ring form type, partially coexisting S of chain like form.

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Two types of liquid are possible in two component system; the one is the type of homogeneous solution and the other is essentially the type of the mixture of two liquids. Recently, phase separation has been found in many kinds of glass. This study has been made to confirm whether phase separation is found in all kinds of glass or not: that is, whether glass is the liquid of the type of homogeneous solution or the liquid of the type of heterogeneous mixture of two liquids.
In this investigation, the glass in the simple CdO-B₂O₃ system having stable separation range (100-60mol% B₂O₃) and glass formation range (60-50mol% B₂O₃), especially 45CdO⋅55B₂O₃ glass, was used. Light scattering and electron micrographs of 45CdO⋅55B₂O₃ glass, showed that, by heat treatment at various temperature below the liquidus temperature, 2CdO⋅3B₂O₃ crystal was formed, but phase separation was never detected in this glass. And an additional experiment in which small amount of TiO₂ was added, showed that TiO₂ has no effect to cause phase separation in such a glass of homogeneous-solution type.
From the aspect of free energy of two component system, there are two types of glass in which the phase separation is not observed. One type of glass forms a liquid of the solution type owing to the decrease of internal energy of the system. In this case, the phase separation is essentially impossible. The other type of glass does not appear to separate owing to the contribution of entropy terms on free energy, although the glass is essentially a liquid of the mixture type. However, our experimental results that the glass does not separate independently of the temperature and the information derived from the phase diagram of this system, suggest that the CdO-B₂O₃ glass on glass-formation range correspond to the liquid of solution type. Thus, it was concluded that glass is not always separated and the kind of glass exist, which forms a homogeneous solutions and can not be essentially separated.

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三二酸化セリウム (Ce₂O₃) の材料物性は, 従来ほとんど検討されていなかった. Ce₂O₃は二酸化セリウム (CeO₂) を水素中1400℃以上で還元して得られる. このようにして得た焼結体および粉末を用いて測定を行ない, 以下の結果を得た.
(1) Ce₂O₃は極めて酸化しやすく, 空気中では室温でも酸化の進行が認められ, 加熱した場合は約60℃以上で急激に酸化しCeO₂になった. また通常の真空中, アルゴン中, 水素中でも数100℃から1000℃の温度では, いくらか酸化して中間相 (CeO_2-x) を生成した. アルカリには不溶, 酸にはゆっくり溶け, 水と反応して水和物をつくることが観察された.
(2) Ce₂O₃の小片を水素気流中, タングステン炉で融点を測定し, 2210±10℃の値を得た. Ce₂O₃は水素中で融点まで安定に存在したが, 中間相は不安定であった.
(3) 熱膨脹の測定から, 線膨脹係数として, Ce₂Oに対しては室温で12.0×10^-6deg^-1, 1350℃で14.8×10^-6deg^-1が, CeO₂に対しては室温で10.0×10^-6deg^-1, 1100℃で13.5×10^-6deg^-1が得られた.
(4) 電気伝導度の対数logσと温度Tとの関係は, 約950℃にクニックを持つ直線で表わされる. σ_300°K=7.7×10^-7Ω^-1cm^-1, σ_1673°K=8.0×10^-2Ω^-1cm^-1で活性化エネルギーは高温域で0.95eV, 低温域で0.40eVで, 低温域では, Ce⁴⁺の混入による一種のホッピング型電導が現われたものとみなされる.
(5) 77°Kから300°Kの間で, Ce₂O₃の磁化 (M) と磁場 (H) の関係および, 1/xとTの関係はいずれも直線的で常磁性的挙動を示した. θ_p=-90°K, μ_eff=2.44 B. M. は理論値と良く一致した.

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Single crystals of spinels, having MgO:Al₂O₃ ratio from 1:1 to 1:3, were grown by flame fusion method. Relations between growth conditions such as growth direction, growth rate and composition, and crystal properties or texture were studied. The results were as follows:
(1) The growth of 1:1 and 1:1.5 spinels to [100] and [110] directions was difficult, and the cracks were often observed for the resulting boules. The growth of 1:3 and 1:2.5 spinels, however, was rather easy. To the [111] direction, the growth of all of the boules was difficult and the cracks were apt to be formed. The side faces of the boules grown to [100] and [110] were {100} and {111} planes, respectively. The shape of the boule grown to [111] was triangular prism.
(2) The composition of boule, 1:3 spinel, was homogeneous. When the composition of boule was close to 1:1, the lower part of the boules was rich in alumina.
(3) In the boules grown to [100], higher etch-pit density area was shown against to [010], [010], [001] and [001] directions by etching of (100) plane.
(4) The mosaic misorientation was deduced from X-ray diffraction topographs, using Berg-Barrett method. 1:2.5 and 1:3 spinels consist of subgrain with high misorientation and each subgrains was not so divided. To the contrary, 1:1 and 1:1.5 spinels consist of subgrain with low misorientation and each subgrains was much more divided.

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