本文關(guān)鍵詞： 合金納米線或管 電化學沉積 陽極氧化鋁模板(AAO) 磁各向異性 熒光強度　出處：《內(nèi)蒙古大學》2015年碩士論文　論文類型：學位論文

【摘要】：稀土元素特有的4f電子層結(jié)構(gòu),賦予它有別于其他元素的物理、化學性質(zhì),在科研領(lǐng)域中倍受人們的重視。本文用電化學沉積法在孔洞均勻的氧化鋁模板內(nèi)組裝La-Ni納米線、納米管和La-Ni:Sm納米線列陣。實驗中用到的測量儀器：掃描電子顯微鏡、透射電子顯微鏡和X射線衍射儀對樣品的形貌和晶體內(nèi)部結(jié)構(gòu)進行掃描；用X射線能量色散儀對樣品成分比例進行粗略測試；測量樣品的磁性能時使用振動樣品磁強計；用熒光光度計(FLS920)測量發(fā)光材料的熒光性能。實驗中我們采用不同孔徑的AAO模板組裝成了La-Ni納米線、納米管列陣。XRD圖和選區(qū)電子衍射圖SEAD表明La-Ni合金納米線和納米管的晶體結(jié)構(gòu)是非晶。磁性測量結(jié)果說明La-Ni合金納米線和納米管都有很強的磁各向異性能,其中形狀各向異性起主要決定作用,并且誘導(dǎo)易磁化軸平行于納米線、管的長軸。將La-Ni合金納米管在氮氣的保護下進行退火,其磁性能發(fā)生了轉(zhuǎn)變,磁各向異性從形狀各向異性起主導(dǎo)作用轉(zhuǎn)變?yōu)殪o磁相互作用起主導(dǎo)作用,且易磁化軸從平行于納米管的長軸轉(zhuǎn)變?yōu)榇怪庇诩{米管的長軸,而磁晶各向異性幾乎不變。同樣用不同孔徑的AAO模板制備了La-Ni:Sm納米線列陣。在未摻雜Sm3+時,La-Ni合金納米線列陣出現(xiàn)了發(fā)光現(xiàn)象,是由于Ni電子的能級躍遷產(chǎn)生的。摻雜Sm3+時,La-Ni合金納米線出現(xiàn)了Sm3+的特征峰,即激發(fā)峰波長為342 nm、360 nm、370 nm、408 nm、432 nm和470 nm,發(fā)生了6H5/2→4K17/2、6H5/2→4D3/2、 6H5/2→6P7/2、6H5/2→4K11/2、6H5/2→4M19/2和6H5/2→4I13/2的能級躍遷；發(fā)射峰波長為572 nm、603 nm和643 nm,對應(yīng)于Sm3+的4G5/2→6H7/2、4G5/2→6H7/2、 465/2→6H9/2的能級躍遷。摻雜不同比例8m3+時,La-Ni:Sm合金納米線列陣在摻雜比例為3：100時熒光強度值最大,之后出現(xiàn)了濃度淬滅現(xiàn)象。摻雜相同比例的Sm3+時,不同溫度下La-Ni:Sm合金納米線列陣的熒光強度出現(xiàn)先增加后減小的現(xiàn)象,在T=400℃時,熒光強度值最大；不同直徑的La-Ni:Sm合金納米線列陣的熒光強度隨直徑的增加,出現(xiàn)先增加后減小的現(xiàn)象,在D=100 nm時,熒光強度值最大。
[Abstract]:The unique 4f electron layer structure of rare earth elements, which gives it physical and chemical properties different from other elements, has attracted much attention in the field of scientific research. In this paper, La-Ni nanowires have been assembled by electrochemical deposition in homogeneous alumina templates. Nanotubes and La-Ni:Sm nanowires. Measuring instruments used in the experiment: scanning electron microscope, transmission electron microscope and X-ray diffractometer to scan the morphology and crystal structure of the sample; The composition ratio of the sample was roughly measured by X-ray energy dispersive instrument, and the vibrating sample magnetometer was used to measure the magnetic properties of the sample. Fluorescence properties of luminescent materials were measured by fluorescence photometer FLS920. In the experiment, La-Ni nanowires were assembled by using AAO templates with different pore sizes. The crystal structure of La-Ni alloy nanowires and nanotubes is amorphous, and the magnetic measurements show that both La-Ni alloy nanowires and nanotubes have strong magnetic anisotropy. The shape anisotropy plays an important role and induces the easy magnetization axis to be parallel to the long axis of the nanowires and tubes. The magnetic properties of the La-Ni alloy nanotubes annealed under the protection of nitrogen have been transformed. The magnetic anisotropy changes from shape anisotropy to magnetostatic interaction, and the magnetization axis changes from the long axis parallel to the nanotube to the long axis perpendicular to the nanotube. The magnetocrystalline anisotropy is almost unchanged. La-Ni:Sm nanowires are also prepared by using AAO templates with different pore sizes. The luminescent phenomena of La Ni alloy nanowires are observed when the nanowires are not doped with Sm3. Sm3 doped La Ni alloy nanowires exhibit the characteristic peak of Sm3, that is, the wavelength of excitation peak is 342 nm ~ 360nm ~ 360nm ~ 370nm ~ (-1) ~ 408nm ~ (2) nm ~ (432 nm), and 6H _ 5r ~ (2) _ 2 occurs. 鈫，

本文編號：1545707