Role of Nd-Ni on structural,spectral and dielectric properties of strontium-barium based nano-sized X-type ferrites

The influence of neodymium and nickel substitution on structural and dielectric parameters was investigated in strontium-barium X-type hexagonal ferrites having composition SrBaCu_2?xNi_xNd_yFe_28?yO₄₆ (x = 0, 0.2, 0.4, 0.6, 0.8, 1 and y = 0, 0.02, 0.04, 0.06, 0.08, 0.1). Sol-gel method was employed for synthesizing these hexagonal ferrites. The XRD plots of all studied materials which were annealed at 1250 °C show single phase characteristics. Lattice parameter ‘c’ increased as a consequence of larger radius of rare earth ion (Nd³⁺) as compared to (Fe³⁺), while lattice parameter ‘a’ showed very small variation. The cell volume was obtained in the range 2508.32–2523.75 (ų). The inclusion of Nd-Ni also affected X-ray density, bulk density and porosity. The FTIR spectroscopy indicated the particular absorption peaks of hexagonal ferrites and it was performed in the range of 500–700 cm^?1. On account of Nd-Ni doping, the dielectric constant, dielectric loss and AC-conductivity showed decreasing trend. The occupancy of Nd³⁺ ions at octahedral site impedes the valence alternation of Fe³⁺; therefore there was decrease in dielectric permittivity. Ac conductivity has been decreased from 9.14 to 6.49 (Ω cm)^?1 at frequency of 2.7 GHz. The Cole-Cole plots of synthesized materials noticeably revealed grain boundary contribution. The appearance of single semi-circle in impedance Cole-Cole graphs confirms the exceptional role of grain boundaries in the conduction process. The considerably lower dielectric parameters of investigated nano X-type ferrites propose their feasibility for high-frequency applications (phase shifters, dielectric resonators, stealth technology etc).     

电化学沉积Nd掺杂ZnO薄膜的结构和光学性质的研究

用电化学沉积方法制备出了Nd掺杂的ZnO薄膜,并研究其结构和光学性质。X-射线衍射谱的结果表明Nd3 替代Zn2 进入到ZnO晶格中,并没有引起杂相的出现。吸收谱的分析表明,随着掺杂浓度的增大,吸收峰向短波长方向移动 ,即发生蓝移。光致发光谱的结果表明随着Nd3 掺杂浓度的增大,紫外峰强度减小,可见光部分强度增大了。     

掺钕介孔硼硅酸盐生物活性玻璃陶瓷骨水泥的制备与性能表征

骨肉瘤是一种常见的恶性骨肿瘤, 常通过手术切除进行治疗。但术后造成的骨缺损难以自愈, 残余肿瘤细胞还会增加复发可能性。本研究开发了一种用于修复骨缺损和协同治疗骨肉瘤的掺钕介孔硼硅酸盐生物活性玻璃陶瓷骨水泥。首先通过溶胶-凝胶法结合固态反应制备了可作为光热剂和药物载体的掺钕介孔硼硅酸盐生物活性玻璃陶瓷微球(MBGC-xNd), 然后将微球与海藻酸钠(SA)溶液混合制备了可同时进行光热治疗和化学治疗的可注射骨水泥(MBGC-xNd/SA)。结果表明掺Nd³⁺赋予微球可控的光热性能, 负载阿霉素(DOX)的微球显示出持续的药物释放行为。此外, 载药骨水泥的药物释放量随着温度的升高而显著增加, 说明光热疗法产生的热量可促进DOX释放。体外细胞实验结果表明, MBGC-xNd/SA具有良好的促成骨活性, 并且光热-化学联合疗法对MG-63骨肉瘤细胞起到了更显著的杀伤作用, 表现出协同效应。因此,MBGC-xNd/SA作为一种新颖的多功能骨修复材料, 在骨肉瘤的术后治疗方面具有良好的应用前景。     

杂质对掺钕磷酸盐激光玻璃光谱性质的影响

综述了过渡金属杂质（Cu,Fe）和稀土杂质（Dy,Pr,Sm,Ce）对掺钕磷酸盐激光玻璃吸收损耗及Nd^3＋荧光猝灭影响的研究状况。     

Effects of Technical Conditions on Structure, Morphology and Crystalline Size of Nanocrystalline Nd-Doped Ceria Powders

Nanocrystalline solid solution CeO2-Nd2O3 powders were prepared by low temperature combustion process.Special attention was paid to the influence of the glycine/metal ratio and calcination temperature on the powders phase structure, morphology and particle size.TG-DSC curves and XRD peaks of different glycine/metal ratio show that smaller particle size can be obtained with a slightly fuel-deficient ratio.XRD results indicate that the as-prepared powders are crystallized in a single fluorite structure.The crystalline size ranges from 9 to 24 nm, which increases with the increase of calcination temperature.The lower SEM images were characterized by the spongy and form-like microstructure of the powders.Organic agent may be gradually eliminated by high temperature calcination process.     

Zn0.98Nd0.02O室温拉曼特性和伏安特性

通过固相反应工艺制备了Zn0.98Nd0.02O纳米颗粒,射频磁控溅射技术在Si(111)衬底上制备了Zn0.98Nd0.02O薄膜。应用XRD、AFM以及拉曼光谱等手段,分析了Zn0.98Nd0.02O纳米颗粒与薄膜的结构,并测试了Zn0.98Nd0.02O薄膜的室温伏安特性。表明Nd掺杂没有改变ZnO纤锌矿结构,Zn0.98Nd0.02O颗粒为纳米多晶粉末态,其薄膜为沿(100)、(101)方向生长的纳米多晶结构,表面形貌粗糙。拉曼光谱分析表明,Zn0.98Nd0.02O颗粒的局部应力增大,晶格畸变缺陷增加,缺陷态比较复杂,导致拉曼峰发生频移。Zn0.98Nd0.02O薄膜的室温I-V曲线表明了Zn0.98Nd0.02O薄膜的非线性导电特性。其非线性导电特性源于,薄膜中的载流子受外加电场在薄膜中所产生热激发进入导带导电,环境光中能量高于ZnO带隙的光子引起的光电导效应,以及薄膜中纳米粒子间的隧穿导电。在光辐照作用下,提高了薄膜内浅施主缺陷浓度,降低了薄膜的表面电阻率,增强了Zn0.98Nd0.02O薄膜的导电能力。     

掺钕材料激光终态能级寿命测量

介绍了目前测量掺钕材料激光终态能级寿命的三种方法,通过对三种测量方法比较,采用间接法测量激光终态能级寿命相对简单易行。     

Zr与稀土Nd复合掺杂对钛酸钡陶瓷结构及介电性能的影响

在1 270℃的烧结温度下,采用固相反应法对BaTiO3粉体进行Nd2O3和ZrO2双施主复合掺杂,合成(Ba0.98Nd0.02)(Ti1–xZrx)O3(BTNZ)陶瓷,研究了Zr掺杂量对BTNZ陶瓷的显微结构及介电性能的影响。结果表明:随着Zr掺杂量的增加,BTNZ陶瓷的介电峰移向室温;加入适量的Zr离子替代BaTiO3中的Ti离子能很好地改善BTNZ陶瓷的介电性能,当Zr掺杂量为x=0.01时,BTNZ陶瓷的相对介电常数可达7 200。     

Nd掺杂TiO2涂层制备与耐蚀性能研究

采用溶胶凝胶-浸渍提拉法在304不锈钢表面制备了纯TiO2涂层与Nd掺杂TiO2涂层,采用SEM、XRD、EDS等测试方法对涂层的形貌、晶体结构、成分进行表征,采用tafel曲线测试涂层耐蚀性能.结果表明:Nd掺杂后,单颗粒子粒径减小,涂层更加均匀致密,TiO2与Nd掺杂TiO2均为锐钛矿结构.在光照条件下,Nd掺杂TiO2涂层的耐蚀性能高于纯TiO2涂层.     

掺Nd的（Sr,Pb）TiO3陶瓷的热敏特性研究

研究了用固相法制备的掺（Ｓｒ，Ｐｂ）ＴｉＯ３陶瓷的热敏特性。结果表明，掺Ｎｄ的（Ｓｉ，Ｐｂ）ＴｉＯ３陶瓷具有良好的ＮＴＣ－ＰＴＣ复合热敏特性，主要参数：Ｔｃ＝１２３℃，ｐＲＴ＝１５０Ωｃｍ，ｐｍｉｎ＝１５．４４Ωｃｍ，α（－）５０＝－３．０６％／℃，α（＋）５０＝７．５７％／℃，降阻后材料仍为典型的ＡＢＯ３型钙肽矿结构；Ｎｄ＾３＋一部分以施主形式进入Ａ位，一部分仍以Ｎｄ２Ｏ３的形式残留在试样中。Ｓ