共查询到19条相似文献,搜索用时 93 毫秒
1.
本文采用水热法,以ZnO为前驱物,添加适量的MnCl2·4H2O、SnCl2·2H2O和MnCl2·4H2O、CoCl2·6H2O、CuCl2·2H2O,3 mol/L KOH作矿化剂,430℃反应24 h,分别合成了Zn1-xMnxO:Sn晶体和Zn1-x-yMnxCoyO:Cu晶体.用扫描电镜(SEM)对合成物形貌进行分析,结果表明,Zn1-MnxO:Sn晶体为六棱柱状晶体,直径约为10 μm,较大面积显露正极面c{0001},同时也显露负极面-c{0001}、正锥面p{1011}、负锥面-p{1011}和柱面m{1010}.Zn1-x-yMnxCoyO:Cu晶体也显露负极面-c{0001}、正锥面p{1011}、负锥面-p{1011}和柱面m{1010},{0001}显露面小于{0001}.X射线能谱(EDS)分析表明晶体主要成分为ZnO,Mn2 、Co2 离子掺杂量超过2%;SQUID磁性测量显示所合成晶体在25 K具有反铁磁特征,高温为顺磁性. 相似文献
2.
水热法合成Mnx Zn1-xO微晶体 总被引:1,自引:1,他引:0
本文采用水热法合成了MnxZn1-xO晶体,水热反应条件为3mol·L-1KOH作为矿化剂,填充度为35;,温度为430℃,在Zn(OH)2中添加一定量的MnO2为前驱物,反应时间为24h.通过X射线能谱仪测量了晶体中的Mn含量,随着前驱物中MnO2含量的增加,晶体中Mn的原子百分比随着增加,Mn最大原子百分比含量超过了2;,晶体的形貌具有纯ZnO晶体的六角柱形特征.显露柱面m{1010}、锥面p{1011}、负极面O面{0001}和正极面{0001}.晶体直径为50~200μm,高度为20~100μm. 相似文献
3.
本文采用高温化学气相输运法,温度970℃,在蓝宝石和石英基片上制备Zn1-xCoxO晶体.电子扫描显微镜(SEM)观察发现,蓝宝石晶片上的晶体形貌较SiO2 晶片上的规整,晶体呈现六棱柱或六棱锥体,一般显露柱面m{101-0}、正锥面p{101-1}、负极面c{0001-}和正极面c{0001},晶体表面光滑.在石英基片上得到的Zn1-xCoxO晶体生长的棱面较模糊,基片的部分晶体非定向密集生长,连续形成薄膜结构.X衍射证实晶体为ZnO纤锌矿结构.X光能谱﹙EDS﹚测量表明 ZnO 晶体有钴离子的存在,且浓度随原料中的Co2O3:ZnO的比值增大而增加 . 相似文献
4.
In掺杂对水热法合成ZnO晶体形貌的影响 总被引:1,自引:0,他引:1
本文采用水热法,在ZnO中添加In2O3为前驱物,3mol/L KOH作矿化剂,温度430℃,填充度35;,反应24h,制备了掺In的ZnO晶体.未掺杂In2O3合成的纯ZnO晶体呈六棱锥状,显露负极面-c{0001}、六棱锥面+p{1011}和-p{1011},一般不显露{0001}面.前驱物中掺杂In2O3所合成的ZnO晶体呈六角片状,直径约为5~20 μm,大面积显露{0001}面,另外还显露正锥面+p{1011}、负锥面-p{1011}和负极面-c{0001}.由此可见In掺杂可以明显的改变晶体的形态,使c轴极性快速生长趋向得到明显改善,有利于降低晶体生长缺陷.当采用ZnO晶片为籽晶时,通过水热反应在晶片上生长了一层掺In的ZnO薄膜,通过Hall参数测量得到晶体膜层的电子迁移率约为22cm2/(V·s),载流子浓度约为2×1020 cm-3,具有良好的导电性,同时也说明In可以微量掺入氧化锌晶体. 相似文献
5.
本文采用水热法,以3mol/L KOH为矿化剂,填充度35%,温度430℃,通过添加适量比例的MgCl2.7H2O和CaO,合成了非极性生长的ZnO晶体。当Mg2 :Zn2 =2%和Ca2 :Zn2 =2~3%时,晶体c轴方向生长速度明显减弱,{0001}方向的极性生长得到控制,所合成的晶体大面积显露正极面 c{0001},同时显露负极面-c{1001-}、正锥面 p{101-1}、负锥面-p{101-1-}和柱面m{101-0}。X光能谱(EDS)没有检测到晶体中含有碱土金属离子。 相似文献
6.
LiOH矿化剂对水热合成ZnO晶体形貌的影响 总被引:1,自引:0,他引:1
本文研究了在430℃,填充度为35用了3mol/L,5mol/L LiOH做矿化剂,所获得晶体均为10μm以下的微晶.当矿化剂为1mol/L LiOH和1mol/L KBr时,所获得晶体同样为几微米的微晶,显露完整的正极面{0001}、负极面{0001}、锥面{1011}和柱面{1010}.矿化剂为3M LiOH和3M KBr时,出现个体较大的晶体,直径超过100μm,显露正极面{0001}、正锥面{1011}和柱面{1010},负极面出现缺损现象.由此说明和K+相比溶液中的Li+不利于生成大尺寸ZnO晶体. 相似文献
7.
水热法合成氧化锌晶体 总被引:15,自引:8,他引:7
本文采用水热法,通过改变矿化剂浓度,合成了具有不同晶体形态的氧化锌晶体.在430℃,填充度为35;,矿化剂浓度为1M KOH时,只合成了氧化锌微晶.氧化锌晶体的长度为几百纳米到几微米,晶体形状为六棱锥体.当矿化剂为3M KOH或2M KOH、1M KBr时,合成了高质量的氧化锌晶体.反应 24h后,合成的最大晶体长度(c轴方向)超过1mm,晶体呈单锥六棱柱体,显露柱面m{1010}、锥面p{1011}、负极面o面{0001}.另外还生成多种不同形态的微晶体,最小几微米,中等的几十微米,为六棱锥体,显露锥面p{1011}、负极面o面{0001},没有显露柱面. 相似文献
8.
采用水热法,以3 mol/L KOH为矿化剂,填充度35%,温度430℃,前驱物Zn(OH)2,比较研究了三种矿化剂条件下合成晶体的形貌和发光性能。三种矿化剂条件分别为样品1,3 mol/L KOH;样品2,3 mol/L KOH,1 mol/LLiOH;样品3,3 mol/L KOH,CaO∶Zn(OH)2=2%(物质的量百分比)。添加适量比例的LiOH或CaO,合成了非极性生长的ZnO晶体,晶体c轴方向生长速度明显减小,所合成的晶体大面积显露正极面c{0001},同时显露负极面-c{0001}、正锥面p{101}、负锥面-p{10}和柱面m{100}。只添加KOH或辅助添加LiOH时,合成晶体的发光光谱中只有可见光谱,无紫外线带边跃迁发光谱,说明晶体缺陷发光中心较多。添加CaO时合成晶体的发光光谱中有较强的紫外带边跃迁发光,说明晶体缺陷发光中心减少。 相似文献
9.
Sn掺杂对ZnO晶体形貌和磁性的影响 总被引:4,自引:4,他引:0
采用水热法,在ZnO中添加SnCl2.2H2O作前驱物,3M KOH作矿化剂,温度430℃,填充度35%,反应24h,合成了掺杂Sn的ZnO晶体。当前驱物中添加SnCl2.2H2O可以明显影响部分晶体形态,使正极面c轴方向的生长速度受到抑制,较大面积显露正极面c{0001},同时也显露负极面-c{000 1}、正锥面p{10 10}、负锥面-p{101 1}和柱面m{10 10}。磁性测量结果显示Sn可微量掺入ZnO晶格中,且呈现顺磁性特征。X射线衍射和X光荧光能谱分析表明,SnCl2.2H2O的添加量较大时,还伴随生成金红相SnO2棒状晶体。 相似文献
10.
本文采用水热法,以3mol/L KOH为矿化剂,填充度35;,温度430℃,在Zn(OH)2中添加SnCl2·2H2O,添加量为Sn2+:Zn2+=2;条件下,合成出ZnO晶体.产物中除了大量短六棱柱形晶体外,还出现了部分冰激凌形晶体.六棱柱形晶体具有典型的ZnO特征,显露正极面c{0001}、负极面-c{000-1}、柱面m{10-10}、正锥面p{10-11}和负锥面-p{10-1-1}.而冰激凌形晶体有明显的六棱锥晶体外壳,X光能谱(EDS)检测证实晶体各部位的组分均为ZnO. 相似文献
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12.
氧化锌单晶的水热生长与结晶习性 总被引:1,自引:1,他引:0
本文应用水热生长法,采用双温区高压反应釜,黄金内衬(φ35mm ×2mm),碱性溶液矿化剂,生长出了毫米级的透明氧化锌单晶,最大单晶可达2mm ×3mm ×6mm.所生长氧化锌晶体为纤锌矿型的六方晶体,晶体呈上部锥形的六棱柱体,{10(1-)1}、{10(1-)0}和{000(1-)}面有较大的显露平面.本文中从温差和填充度方面研究了实验条件对ZnO晶体的生长及其形貌的影响,使用黄金内衬前后的结果表明,用贵金属内衬可以有效阻止釜内壁杂质的进入,使晶体完整透明. 相似文献
13.
采用水热法以CoO、ZnO混合为前驱物制备了ZnO晶体,矿化剂为6 mol/L KOH,填充度70;,温度430℃,两种样品CoO、ZnO组分物质的量百分比分别为0.5∶1和1∶1.当前驱物为nCo∶nZn=0.5∶1时,合成出Zn1-xCoxO晶体,Co元素掺杂量分别为6.83 at;和9.30 at;.当前驱物中nCo∶nZn=1∶1时,Zn1-xCoxO晶体中Co掺杂比例达到9.31 at;,同时伴有Co3O4生成,其中Zn掺杂比例达到14.59 at;,SEM显示,所制备的Zn1-xCoxO具有明显的ZnO晶体特征,形态完整,最大尺度约为50 μm.SQUID测量显示,生成物中Zn1-xCoxO晶体具有顺磁性,Zn1-xCoxO和Co3-xZnxO混合晶体也显示为顺磁性. 相似文献
14.
Mn-Bi alloy films were prepared by simultaneous vacuum deposition at liquid N2 temperature and their structures were investigated by transmission electron microscopy and electron diffraction. Films with compositions in the range of 34 to 63 at% Mn have the Bi lattice structure at room temperature. Films with composition in the range of 68 to 95 at% Mn show diffuse haloes at room temperature. When they are heated above room temperature, those in the range of 70 to 85 at% Mn show nucleation and grain growth crystallization, whereas the films of 68 and 95 at% Mn show only grain growth crystallization. The films in the range of 70 to 85 at% Mn are concluded to be amorphous at low and at room temperature. Some of the crystals obtained by nucleation and the grain growth crystallization grow as large as 10 μm in length. Their diffraction patterns are not ascribable to reported crystals in this alloy system. 相似文献
15.
S. Dinakaran S. Verma S. Jerome Das S. Kar K. S. Bartwal 《Crystal Research and Technology》2010,45(3):233-238
Growth kinetics of zinc tris(thiourea) sulphate (ZTS) single crystals was imaged in two different growth geometries using laser shadowgraphy technique. Growth rates of the {010} and {001} faces were computed as a function of supersaturation. The time evolution of polar morphology of ZTS crystal based on the growth rates is presented. Except (00 ) face, all the other three faces are found to have a dead zone resulting in large induction period of growth. The anisotropy in the growth rates of the (001) and (00 ) faces was very high, resulting in polar morphology. Different chemical environments on two sides of the (001) slice are suggested as the possible cause for the polar morphology of the crystals. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
16.
LiGaO2 forms a single eutectic with PbO/B2O3 (molar ratio 9:4). A nearly linear slope of the liquidus curve is followed by a steep rise of the temperature coefficient of solubility. The solvent power at 1300°C is 0.35 g LiGaO2/g PbO, B2O3; from 1000 to 1300°C there exist only poor differences in solubility of LiGaO2 and LiAlO2 in PbO/B2O3. LiGaO2 crystals up to 1 p in weight grew spontaneously by slow cooling from fluxes or by evaporation of the solvent, those of about 1–1.5 p from seeds by cooling stirred fluxes. LiAlO2 crystals are essentially smaller (6 mm). – By partial substitution of Ga2O3 by Al2O3 mixed crystals LiAlxGa1−xO2 result. In the case of x ≦ 0.5 the coefficient of segregation remains ≦1. The al concentrations along the polar axis decrease by more than 25 p.c., perpendicular to [001] they keep constant till to the crystal surface. – Crystals show hypermorphism from mm2 to mmm. With high initial exceedings only {110} and {011}, with lower ones also {120}, {130}, {210} and {310} as well as the reduced {100}, {010} combinations are observed. – LiGaO2 crystals grow by nucleous, sceletal or faceted growth resp. during the cooling period. – Primarily at 1270°C formed nuclei up to 1150°C grow to critical dimensions (≈0.5 mm) and develop to the main branch along [001]. Primary branches deflect to [010]. The convex secondary branches intergrow along (110), often including flux. With decreasing temperature a new crystallisation front is formed at the periphery leading to a stable faceted growth at about 1000°C. 相似文献
17.
The equilibrium shape of β-copper-phthalocyanine single crystals is obtained by the method of the PBC-vectors according to HARTMAN and PERDOK . These results agree well with the experimentally found growth shape of single crystals grown in the vapour phase. The crystals are of needle-like shape. The crystal surfaces are lattice planes of the kind {001}, {201 }, {100}, {101 } and {110}. The ratio of length to width of the crystals is influenced by the inert gas pressure during the growth process. This dependence is caused by the diffusion of the nutrient. 相似文献
18.
Magnetization and structural studies of Mn doped ZnO nanoparticles: Prepared by reverse micelle method 总被引:1,自引:0,他引:1
O.D. Jayakumar I.K. Gopalakrishnan R.M. Kadam A. Vinu A. Asthana A.K. Tyagi 《Journal of Crystal Growth》2007,300(2):358-363
Single phase Mn (2.5 at%) doped ZnO nanocrystalline samples were synthesized by reverse micelle method as characterized by Rietveld refinement analysis of X-ray diffraction data, high resolution transmission electron microscopy and selected area electron diffraction analyses. The X-ray photoelectron spectroscopy and electron paramagnetic resonance (EPR) studies indicated that manganese exist as Mn2+ in ZnO lattice. DC magnetization measurements as a function of field and temperature, of 2.5 at% Mn doped ZnO nanoparticles annealed at 675 K, showed room temperature ferromagnetism (RTF). This observation is further confirmed by the EPR spectrum of the sample, which shows a distinct ferromagnetic resonance signal at room temperature. These results indicate that the observed RTF in Mn-doped ZnO may be attributed to the substitutional incorporation of Mn at Zn sites. 相似文献
19.
Marian Szurgot 《Crystal Research and Technology》1995,30(5):621-628
Microtopography of {100}, {110}, {111}, and {210} surfaces of sodium chlorate crystals etched in various solvents has been studied by optical microscopy. It has been established that etch pits formed on left- and right-handed crystals are chiral, and directions of dissolution steps reveal bond chains of the structure. 相似文献