掺纳米Al2O3的纳米ZrO2(4Y)固体电解质的电性能

以纳米ZrO2(4Y)粉和纳米Al2O3粉为原料, 单轴成型, 1 200, 1 300 ℃无压烧结. 对掺不同质量分数(0.0～5.0%)Al2O3的ZrO2(4Y)烧结体, 用XRD, SEM和TEM研究了相组成和微观结构. 在不同温度下(300～1 000 ℃)测试了交流阻抗谱, 发现掺很少量的纳米Al2O3可降低ZrO2(4Y)的晶粒电阻. 但随着Al2O3掺入量的增加, 晶界电阻增大, 晶粒电阻也有所回升. 晶粒和晶界电导活化能则随Al2O3掺入量的变化不大. 对1 200 ℃,2 h烧结样品, 在1 000 ℃时, 掺0.5% Al2O3的ZrO2(4Y)样品有最大电导率, 为3.8×10-2Ω-1·cm-1.     

Al3(SO4)2(OH)5H2O与α-Al2O3晶须的制备及其生长机制

采用液相沉淀及烧结方法制备了Al3(SO4)2(OH)5H2O与α-Al2O3晶须,样品采用XRD、SEM及G-DTA等对样品物相、形貌及热行为进行了表征,结果表明晶须样品的分散性好,粒度分布均匀、表面光滑,Al3(SO4)2(OH)5H2O与α-Al2O3晶须品质优良.又从“生长基元”角度出发,讨论了Al3(SO4)2(OH)5H2O晶须的形成机制,其生长过程是生长基元是八面体[Al-(OH)6]3-与HSO4-往某一晶面稳定叠合生长的结果,Al3(SO4)2(OH)5H2O晶须经热分解后,其形貌不变,最终变为α-Al2O3晶须.     

Y2O3-Bi2O3催化剂制备及其可见光催化降解2,4-二氯苯酚的研究

采用高温固相法合成一系列不同质量比的Y2O3-Bi2O3复合可见光复合催化剂,在日光色镝灯照射下,以2,4-二氯苯酚的可见光催化降解为目标反应,研究了Bi/Y质量比及焙烧温度对Y2O3-Bi2O3复合催化剂的结构及活性的影响.结果表明,复合光催化剂Y2O3-Bi2O3的最佳焙烧温度1023 K,焙烧时间2.5 h,最佳...     

Al2O3/Al2O3-ZrO2(3Y)层状纳米陶瓷复合材料的显微结构及弯曲强度

在Al2O3-ZrO2(3Y,即含3%Y2O3,摩尔分数,下同)纳米陶瓷的基础上,以原位合成的Al2O3和Al2O3-ZrO2(3Y)纳米粉体为原料,采用干压成型及热压烧结的方法制备了Al2O3/Al2O3-ZrO2(3Y)层状纳米陶瓷复合材料,研究了ZrO2(3Y)含量对材料显微结构及力学性能的影响.结果表明:复合材...     

凝胶成型Al2O3-(30vol%)MgO·1.35Al2O3泡沫陶瓷的研制

以板状刚玉和富铝尖晶石为主原料,采用泡沫浸浆凝胶工艺制备了Al2O3-(30 vol%)MgO@1.35Al2O3泡沫陶瓷.研究了分散剂AN-2000与pH值对Al2O3-(30vol%)MgO@1.35Al2O3混合浆料流变特性的影响.在pH值=9.5、AN-2000添加量为0.4 mL@m-2的条件下制备的粘度为O.14 Pa@s,固相体积分数为55%的Al2O3-(30vol%)MgO@1.35Al2O3混合浆料,通过有机泡沫浸浆、引发凝胶反应、湿坯干燥、排胶和烧结,制备出了气孔率为89.3%,强度为5.2 MPa的Al2O3-(30vol%)MgO@1.35Al2O3泡沫陶瓷.     

注射成形AlN-Y2O3陶瓷的结构与性能

采用粉末注射成形方法制备了具有高导热性能的AlN陶瓷导热材料, 研究了烧结温度对注射成形AlN陶瓷致密化的影响;研究了添加不同质量分数Y2O3对注射成形AlN陶瓷的晶界第二相、热导率和显微结构的影响. 结果表明在本实验研究条件下, 当烧结温度在1 850 ℃时, AlN的相对密度已经能够达到99.5%;Y2O3的添加量对AlN的晶界第二相的影响和传统AlN制备工艺中有较大的不同, 在Y2O3质量分数为3%时就有多余的Y2O3成为晶界相, 这主要是注射成形工艺中会引入大量的残碳造成的. 注射成形AlN陶瓷工艺中氧离子是否扩散进入晶格中对AlN陶瓷的热性能有一定影响. 当Y2O3质量分数为5%时, AlN中的晶界第二相主要为YN和Y2O3, 样品具有最高的热导率167.5 W/(m*K).     

沉淀法制备Al2O3-ZrO2-Y2O3复合粉体的固相反应

采用化学沉淀法制备了不同配比的Al2O3-ZrO2-Y2O3复合粉体.通过X射线衍射研究了热处理过程中各物质之间的反应顺序及复合粉体的物相组成,结果表明升温过程中Y2O3优先与ZrO2反应生成固溶体,温度较高时,剩余Y2O3与Al2O3反应生成钇铝石榴石YAG;不同的制备工艺没有改变各物质之间的固相反应顺序,但影响了复合粉体中各物相的相对含量.     

Y2O3掺杂对(Bi0.5Na0.5)0.94Ba0.06TiO3无铅压电陶瓷性能的影响研究

采用传统固相反应法制备了Y2O3掺杂(Bi0.5Na0.5)0.94Ba0.06TiO3(简写为BNBT6)陶瓷[简称为BNBT6-x(wt%)Y2O3陶瓷].研究了Y2O3 (0.2wt%～0.8wt%)掺杂对BNBT6陶瓷的结构、介电、压电、铁电性能的影响.结果表明,所有Y2O3掺杂陶瓷样品均形成了单一的钙钛矿结构;陶瓷的介电、压电、铁电性能受Y2O3掺杂的影响较为显著:当掺杂0.4wt%Y2O3时,10 kHz频率下测得的室温εr达到1530,且tanδ较小,为0.050,d33达到152 pC/N,kp=0.27,Qm=134.掺杂0.2wt%的Y2O3时BNBT6陶瓷的d33为145 pC/N,kp增大到0.29,Qm达到173,tanδ为0.053;掺杂适量Y2O3的BNBT6陶瓷铁电性能也得到改善.     

溶胶-凝胶法制备Y_2O_2S:Eu~(3+),Mg~(2+),Ti~(4+)红色长余辉发光粉及其发光特性

以金属硝酸盐和钛酸丁酯为原料,乙酰丙酮为螯合剂,采用溶胶-凝胶法制备了Y2O2S:Eu3+,Mg2+,Ti4+红色长余辉发光粉体。采用X射线衍射仪、扫描电子显微镜和荧光分光光度计对不同温度合成的样品性能进行测试与表征。结果表明:干凝胶在600℃保温2 h生成了立方相的前驱体Y2O3:Eu3+,Mg2+,Ti4+。前驱体在1050～1150℃硫化后的产物为Y2O3与Y2O2S的混合相,在1 200℃时,硫化生成纯相的Y2O2S:Eu3+,Mg2+,Ti4+,产物平均粒径约为150nm,1300℃时再次出现Y2O3相。与高温固相法相比,溶胶-凝胶法制备的样品主激发峰出现蓝移,主发射峰位于616nm和626nm处,对应于Eu3+的5D0→7F2跃迁;硫化温度为1200℃时,样品的余辉时间为40min。     

稀土固体超强酸Nd2O3-Fe2O3/SO2-4的制备、表征及催化合成邻苯二甲酸二丁酯的研究

采用甘氨酸-硝酸盐法(GNP)制备稀土复合氧化物粉体Nd2O3-Fe2O3,用不同浓度的硫酸浸渍,经焙烧、活化,制得固体超强酸Nd2O3-Fe2O3/SO2-4.通过XRD等对超强酸物相及微结构进行了表征;通过邻苯二甲酸二丁酯的催化合成,研究了催化剂的催化性能.结果表明,最佳催化剂的组成是NdFe物质的量比为120;活化温度600℃;浸渍酸浓度2.0mol·L-1;活化时间4h.优化反应条件下,邻苯二甲酸二丁酯的产率为98.8%.     

掺杂Eu~(3+)或Tb~(3+)的(Gd,Lu)_2O_3粉体的发光性能

采用高温固相法在空气中合成了(Od,Lu)2O3,(Gd,Lu)2O3:Eu3+和(Gd,Lu)2O3:Tb3+系粉体.研究了二元系中Lu2O3的摩尔分数对抑制Gd2O3高温相变、粉体的发光性质和光谱性质的影响.结果表明:在(Gd,Lu)2O3系粉体中,当Lu2O3的摩尔分数(下同)大于40%时,能在煅烧温度不低于1 700℃情况下,抑制Gd2O3的相变得到利于制备透明陶瓷的立方相结构.而且随着Lu3+离子的浓度增加,先后观察到红移和蓝移现象;在(Gd,Lu)203:Eu3+系粉体中,粉体的发光强度随着Lu3+掺杂量增加而减小,Eu3+的最佳掺杂量为7%;在(Gd,Lu)2O3:Tb3+系粉体中,Tb3+离子的最佳掺量为1%.     

Influence of Microstructure Modulation of Er~（3＋）-Doped Al_2O_3 on the Photoluminescence Performance

采用溶胶–凝胶法分别制备了掺不同摩尔分数Er3＋的Er3＋：Al2O3粉末和不同摩尔分数Y3＋的0.5%Er3＋：Al2O3（Y3＋：0.5%Er3＋：Al2O3）粉末。利用Y3＋与Al3＋的半径差异,通过共掺不同掺量的Y3＋来调制Al2O3的微结构,用X射线衍射和透射电子显微镜分析样品的结构特征,并通过光致发光光谱研究样品的光致发光特性。结果表明：不同Y3＋和Er3＋共掺杂的Y3＋：Er3＋：Al2O3样品均以-Al2O3为主相;随着Y3＋掺量的增加,Al2O3的晶格缺陷逐渐增多;样品的荧光强度、发射谱宽度及荧光寿命也都随着Y3＋掺量增大而增大。通过Y3＋掺量调制Er3＋所处微结构环境的方法有效地改善了Er3＋：Al2O3材料的发光特性。     

Tetragonal-to-Monoclinic Phase Transitions in Nanocrystalline Rare-Earth-Stabilized Zirconia Prepared by a Mild Hydrothermal Method

Nanocrystalline 4-mol%-Sc₂O₃-stabilized zirconia (4ScSZ) and 4-mol%-Y₂O₃-stabilized zirconia (4YSZ) powders were prepared by a mild urea-based hydrothermal method. The as-prepared 4ScSZ and 4YSZ powders behaved with different tetragonal–monoclinic ( t – m ) transitions on calcination at temperatures between 400° and 1400°C. For the as-calcined 4ScSZ samples, the monoclinic phase fraction varies discontinuously with increasing temperature, i.e., first increases, then decreases, and finally increases again; whereas the monoclinic phase content reduces monotonously for the as-calcined 4YSZ samples, and only tetragonal phase is present over 1000°C. Such interesting results can be explained satisfactorily by considering the combined influences of crystallite size effect, microstrain, and the stabilization effect of the dopant. The microstrain relaxation is mainly responsible for the unusual phase transition in the 4ScSZ samples, while for the 4YSZ samples, the microstrain effect and crystallite size effect can be masked by the stabilization effect of the Y₂O₃ dopant due to its stronger stabilization capability.     

Y_2O_3：Eu~（3＋）@Gd_2O_3核壳结构发光材料的制备与浓度猝灭

采用均相沉淀法制备均匀球形的Y2O3：Eu3＋@Gd2O3核壳结构纳米发光材料,用X射线衍射、红外光谱、扫描电镜、X射线光电子能谱及荧光光谱等表征样品的形貌、结构及发光性能。结果表明：Y2O3：Eu3＋表面成功包覆了Gd2O3,包覆后仍为均匀的球形,包覆层厚度约为5nm;包覆前后样品的猝灭浓度均为7%（摩尔分数）,包覆...     

Effect of Al_2O_3-ZrO_2 Composite Powder on Thermal Shock Resistance of ZrO_2 Sizing Nozzles

ZrO_2 sizing nozzles with a basic formulation were prepared using 45%( by mass,the same hereinafter)( Mg,Y)- PSZ aggregate,55%( Mg,Y)- PSZ fines and 5% PVA binder. Al_2O_3-ZrO_2 composite powders( 3%,6%,9% and 12%) prepared by sol- gel method were added to replace the equal amount of( Mg,Y)- PSZ fines. Effects of Al_2O_3- ZrO_2 composite powders on physical properties,phase composition and microstructure of the ZrO_2 sizing nozzles were studied.The results show that: the performances of the modified sizing nozzles with 3% Al_2O_3-ZrO_2 composite powder are better than those of the nozzles without composite powder used in current production process,and the thermal shock resistance of the former nozzles is six times of that of the latter one.     

Al2O3掺杂YSZ的电性能

研究了Al2O3掺杂对Y2O3稳定的ZrO2材料电导性能的影响。因为Al与自由氧离子空穴缔合的能力大于Y，所以YSZ的晶粒电导随Al2O3含量的增大而减小。Al2O3一方面能清除晶界上的SiO2，同时又与晶界中的氧离子空穴缔合，在这两方面影响下，随Al2O3含量的增大，晶界电阻先减小后增大。     

Phase transformation of FeCr2O4 to (Fe,Cr)2O3 solid solution pigment powders: Effect of post-heating temperature

Iron chromite powders were synthesized via solution combustion route using iron(III) nitrate nonahydrate and chromium(III) nitrate nonahydrate as starting materials, as well as glycine–urea, glycine–citric acid, and glycine–ethylene glycol mixtures as fuels. The effect of postheating at different temperatures on the structure, molecular, microstructure, and chromatic properties of powders and tiles colored by in-glaze powders was studied. The X-ray diffraction patterns showed that as-synthesized powders were obtained in crystalline FeCr₂O₄ phases moreover, postheating of the powders led to d-space shift and oxidation and formation of (Fe,Cr)₂O₃ solid solution phase regardless of fuel type. Phase transformation of FeCr₂O₄ to (Fe,Cr)₂O₃ solid solution was observed at 500/750°C depending on the dominant phase of as-synthesized particles. Fourier transform infrared analysis illustrated that the band positions of octahedral M–O and tetrahedral M–O bonds were shifted due to Fe cations movement from their position and lattice shrinkage by increasing of post-heating temperature. Moreover, scanning electron micrographs showed that Fe_0.7Cr_1.3O₃ semispherical fine particles were formed from porous spongy FeCr₂O₄ particles due to oxidation and phase transformation during the postheating. Furthermore, chromatic properties of the samples were represented. The color properties of the pigments showed that the formation of brown pigments is provided with the phase transformation from FeCr₂O₄ to (Fe,Cr)₂O₃ at a temperature of up to 750°C. Moreover, increasing the color purity to this temperature is related to the removal of residual carbonaceous matters. The chromatic properties of the glazed tiles colored using the pigments showed that postheating between 250 and 500°C led to more brown appearance.     

纳米粉体Y_2O_3:Ti~(3+),Pr~(3+)的光谱性能

采用共沉淀法在氮氢气氛中制备出Y2O3:Ti3+,Pr3+纳米粉体,通过XRD、TEM方法确认了它的晶相与晶粒尺寸,测量了它的激发与发射谱,并与Y2O3:Ti3+纳米粉体的光谱进行了比较。结果显示:共掺Pr3+仅在281nm处产生了激发峰,而在蓝绿光区没有产生激发峰,以致365～480nm的光激发不出Pr3+的特征红荧光。表明:共掺Pr3+的Y2O3:Ti3+用作白光LED荧光粉,难以改善发光性能。     

添加Y2O3对ZrN(ZrON)-SiAlON性能的影响

为了以较低成本制备较高性能的ZrN(ZrON)-SiAlON复合陶瓷材料,先以粉煤灰、锆英石和活性炭为主要原料,经碳热还原氮化法合成ZrN-SiAlON复合粉;然后在ZrN-SiAlON复合粉中添加不同量(质量分数分别为0、5%、10%)的Y2O3,在1500℃保温1 h埋碳烧结制备了ZrN(ZrON)-SiAlON复合陶瓷材料,并研究了ZrN(ZrON)-SiAlON复合陶瓷材料的相组成、烧结性能和力学性能等。结果表明:Y2O3可促进ZrN和β-SiAlON等主晶相的形成,同时促进材料的烧结致密化。添加5%(w)的Y2O3制得的ZrN(ZrON)-SiAlON复合陶瓷材料的显气孔率为5.3%,体积密度为3.47 g·cm-3,常温耐压强度为29.4 MPa,性能较优。     

球形纳米氧化钇的制备与表征

以尿素为沉淀剂,硝酸钇为钇源,十六烷基三甲基溴化铵为分散剂,采用均相沉淀法制备球形纳米氧化钇粉体,研究了反应物浓度比、表面活性剂用量、反应时间、搅拌转速、反应温度对氧化钇形貌及粒径的影响。通过激光粒度分析、X射线衍射（XRD）分析、扫描电镜（SEM）分析、傅里叶红外光谱（FTIR）分析等手段对样品进行表征。结果表明,反应物浓度比、反应时间、搅拌转速、反应温度会影响粉体的尺寸,适量CTAB的加入可显著降低氧化钇的粒径;在最佳工艺条件下,可制得粒径大小为110~130 nm的球形氧化钇粉体。