FullProf School China

RODRIGUEZ-CARVAJAL Juan

RODRIGUEZ-CARVAJAL Juan is the author of FullProf, one of the most used powder diffraction computer programs in the world. (More than 6400 citations, WoS, of the article Physica B 192, 55 (1993); about 12000 citations of the use of the program in Google Scholar)

Juan works at the Institute Laue-Langevin as Staff Scientist. He has full experience in the following areas: Powder and single crystal x-rays and neutron scattering; Symmetry analysis, crystallography and magnetism; Oxides presenting remarkable properties(superconductivity, giant magnetoresistance, charge, spin & orbital ordering.); Computer programming and data analysis.; Neutron diffraction instrumentation.

Course Introduction

1Introduction to FullProf SuiteSep 22 Replay
2Introduction to WinPLOTRSep 23 Replay
3Indexing powder diffraction dataSep 24 Replay
4Ab-initio structure determinationSep 27 Replay
5The Rietveld Method  Sep 28 Replay
6Strategy for Rietveld Refinement    Sep 29 Replay
7Post refinement calculations: GFourier, Bond_StrSep 30 Replay
8 Study of Micro-Structural Effects using Powder Diffraction-IOct 11 Replay
9Study of Micro-Structural Effects using Powder Diffraction-IIOct 12 Replay
10Introduction to Magnetic Structures DeterminationOct 13 Replay
11Q & AOct 13Replay

Attendence Note

  • This course is sponsored by International Office of University of Science and Technology Beijing, as part of the “Go Beyond International Course”.
  • Due to the course capacity, only 40 participants will be engaged in the ZOOM live course, in which they could ask for guidance and explanations from Juan. Please fill in the form and you will be informed about the remaining vacancies.
  • The course will also be simultaneously broadcasted via Tencent meeting.
  • The latest news and the Tencent meeting ID will updated in this webpage.

腾讯会议ID: 576 8853 8828

联系人：刘泉林 宋振

Resources

Demos-1下载

https://workshops.ill.fr/event/162/page/68-documentation

Talks-1-4下载
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新型杂化卤素钙钛矿中的构效关系

南方科技大学：毛陵玲

毛陵玲博士于2018年在美国西北大学获得无机化学专业博士学位，2018至2021年于美国加州大学圣塔芭芭拉分校材料研究院从事博士后研究，主要研究新杂化钙钛矿材料的合成和表征及构效关系和光电器件应用。近年来发表了30篇文章和一项专利授权，其中8篇第一作者论文发表在JACS（5篇为ESI高被引），1篇发表在Chem（封面文章），总引用超过2400次，h-index为19（Google scholar 统计）。2020年入选海外高层次人才计划青年项目，2021年加入南方科技大学化学系，任副教授。

报告内容：有机-无机杂化卤素钙钛矿由于其高效的光电转化效率成为近年来的研究热点。其中研究新型杂化钙钛矿中的构效关系是加强新材料设计和提升器件效率的重要手段。在本次报告中，我们将聚焦一系列新型钙钛矿材料及衍生物的构效关系，包括：1.Dion-Jacobson DJ类型的二维杂化铅碘化物，其结构通式为A＇An-1PbnI3n+1 (A＇= 3-(aminomethyl)piperidinium (3AMP)或4-(aminomethyl)piperidinium (4AMP),A = methylammonium (MA))；2.杂化铅氯、溴化合物；3.杂化二维双钙钛矿材料；4.杂化锰溴化物。在新的DJ体系当中，发现其层间距及无极框架的扭曲程度有所缩小，使带隙系统性地缩小。在杂化铅氯、溴化合物中，体现出宽带发射发白光，其半峰宽与结构的扭曲程度直接相关。在最近的一系列锰溴化合物中，发现通过有针对性的改变有机阳离子的价态，官能团和几何构型，可以直接改变自组装形成的晶体结构中的Mn-Mn距离。并且Mn-Mn距越远，其荧光量子产率越高。我们通过系统性地理解新型金属杂化材料中的结构与其光学性质的关系，为下一代新型光电材料奠定了坚实的基础和提供了新的思路。

报告时间：2021年5月27日

地点：主楼313大会议室

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Efficient Near‐infrared Pyroxene Phosphor LiInGe2O6:Cr3+ for NIR Spectroscopy Application

April 2021, Journal of the American Ceramic Society.https://doi.org/10.1111/jace.17856

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Broadband near-infrared phosphors are essential to realize nondestructive analysis in food industry and biomedical areas. Efficient long-wavelength (>830 nm) phosphors are strongly desired for practical applications. Herein, we demonstrate an efficient broadband NIR phosphor LiInGe2O6:Cr3+, which exhibits a broad NIR emission peaking at ~880 nm with a full width at half maximum of 172 nm upon 460 nm excitation. The internal/external quantum efficiencies of LiInGe2O6:Cr3+ are measured to be 81.2% and 39.8%, respectively. The absorption of the phosphor matches well with commercial blue LEDs. Using the fabricated phosphor converted LED illuminating human palm, distribution of blood vessels can be clearly recognized under a NIR camera. These results indicate that LiInGe2O6:Cr3+ is a promising candidate to be used in future non-destructive biological applications.

Color-Tunable Persistent Luminescence of Ca10M(PO4)7:Eu2+(M = Li, Na, and K) with a β-Ca3(PO4)2 -Type

Inorg. Chem. 2021, 60, 6, 3952–3960.https://doi.org/10.1021/acs.

Eu2+-activated Ca10M(PO4)7 (M = Li, Na, and K) phosphates have been explored extensively because of their tunable emission wavelengths and excellent luminescence performances. Herein, the persistent luminescence (PersL) properties of Eu2+-doped Ca10M(PO4)7 phosphors with a β-Ca3(PO4)2-type structure are reported. With the variation of alkali metal M from Li to Na and to K, the PersL color can be adjusted sequentially from yellow to white and to blue, and the persistent durations are prolonged significantly from about ∼61 s for Ca9.997Li(PO4)7:0.003Eu2+ to ∼1950 s for Ca9.999Na(PO4)7:0.001Eu2+ and to ∼7440 s for Ca9.9995K(PO4)7:0.0005Eu2+ at the threshold value (0.32 mcd/m2) after 254 nm irradiation. The trap depths are estimated according to the thermoluminescence glow curves with various heating rates. Comparing the thermoluminescence excitation and photoluminescence excitation spectra, it can be verified that there are two sources of ionized electrons in the charging process: one is excited from the valence band to the conduction band (CB) and the other is excited from the 4f ground state of Eu2+ to the higher 5d levels or directly to the CB. Finally, the PersL mechanism is proposed. This work is expected to motivate more research of Eu2+-doped phosphate-based PersL materials, as well as contributes to the understanding of the PersL mechanism of Eu2+-doped phosphors.

A Broadband Near-Infrared Phosphor Ca3Y2Ge3O12:Cr3+ with Garnet Structure

Journal of Alloys and Compounds, Volume 863, 15 May 2021, 158699.https://doi.org/10.1016/j.jallcom.

Fig. 1

Near-infrared phosphor (NIR) integrated light-emitting diode (LED) has ideal application prospects in the fields of food inspection and medical imaging. Herein, we have synthesized a garnet-type Ca3Y2Ge3O12:Cr3+ NIR phosphor using solid state reaction method. Broadband NIR emission ranging from 700 to 1100 nm with a peak located at 800 nm indicates a weak crystal field strength for Cr3+, which occupies the six-coordinated Y3+ site. Moreover, the phosphor has satisfactory luminous intensity showing 81%/10% internal/external quantum efficiency and excellent luminescence thermal stability. Our work provides an excellent NIR phosphor choice for NIR LED devices.

Site engineering strategy toward enhanced luminescence thermostability of a Cr3+-doped broadband NIR phosphor and its application

Graphical abstract: Site engineering strategy toward enhanced luminescence thermostability of a Cr3+-doped broadband NIR phosphor and its application
Efficient broadband near-infrared (NIR) light sources are urgently needed for emerging applications in medicine, food analysis, and others. Nevertheless, the performance is limited by luminescence efficiency and thermostability in state-of-the-art broadband NIR phosphors. Here we demonstrate an effective strategy for achieving efficient and thermostable broadband NIR emission by site engineering in a SrGa12O19–LaMgGa11O19:Cr3+ system. Due to the structure symmetry promotion, the end-member SrGa12O19:Cr3+ shows excellent luminescence thermostability, i.e., higher luminescence quenching temperature and more remarkable color stability compared with LaMgGa11O19:Cr3+. At 500 K, the integrated PL intensity remains 86.5% of that at 290 K. Fine local structure, photoluminescence spectra and luminescence decay curves together support that the optically activated Cr3+ centers are reduced due to site symmetry change in SrGa12O19:Cr3+, leading to the remarkable luminescence thermostability. Finally, we have fabricated NIR pc-LEDs with commercial blue-light-emitting InGaN chips (450 nm), showing that SrGa12O19:Cr3+ has a high external quantum efficiency of 45% and has great potential in high-power and efficient pc-LED applications.

Structural Confinement for Cr3+ Activators toward Efficient Near- Infrared Phosphors with Suppressed Concentration Quenching

Trivalent chromium ion-doped near-infrared (NIR) phosphors have been widely studied due to their tunable emission wavelengths and broad applications. High Cr3+ concentration can improve absorption efficiency but generally results in low emission intensity due to the concentration quenching effect. Herein, we report a series of efficient NIR phosphors with suppressed concentration quenching, Sr9M1–x(PO4)7:xCr3+ (M = Ga, Sc, In, and Lu), showing a broadband NIR emission ranging from 700 to 1100 nm peaking at 850 nm upon the 485 nm light excitation. The emission peak position is almost independent of the type of M ion and the Cr3+ dopant content, and the type of M ion has little influence on the luminescence thermal quenching, indicating that [MO6] octahedra are rigid enough to keep octahedral volumes and average M3+–O2– distances nearly constant owing to the formation of the framework structure on Cr3+ substitution. The NIR emission intensities monotonously increase with the Cr3+ content increasing from 0 to 80% with suppressed concentration quenching, the intensity of Sr9Cr(PO4)7 still maintains 84.23% of Sr9Ga0.2(PO4)7:0.8Cr3+ phosphor, and the thermal quenching behavior is slightly dependent on x; these effects can be attributed to the suppressed energy transfer due to the structural confinement effect. The optimal sample, Sr9Ga0.2(PO4)7:0.8Cr3+, has an internal/external quantum efficiency of 66.3%/29.9%. Finally, we fabricate a NIR phosphor-conversion light-emitting diode and demonstrate its applications in nondestructive examination and medical fields.

Tuning luminescence from NIR-I to NIR-II in Cr3+-doped olivine phosphors for nondestructive analysis

Journal of Materials Chemistry C .Issue 16, 2021

Graphical abstract: Tuning luminescence from NIR-I to NIR-II in Cr3+-doped olivine phosphors for nondestructive analysis

The practical application of near-infrared (NIR) phosphors is hindered due to their limited light emitting region and narrow bandwidth. Here, we report a series of Cr3+-doped olivine phosphors, (Mg1−xLix)(Mg1−xScx)GeO4:Cr3+, with tunable luminescence from NIR-I to NIR II based on crystallographic site engineering. By using a [Li+–Sc3+] unit substituting for a [Mg2+–Mg2+] unit, the NIR luminescence can be largely tuned from 940 nm to 1110 nm, and the corresponding FWHM can be modified from 236 to ∼300 nm. The internal quantum efficiency (IQE) and external quantum efficiency (EQE) of Mg2GeO4:1% Cr3+ were measured to be 48.19% and 16.38%, respectively. The photoluminescence of the phosphors matches well with the absorption of several functional groups. By measuring the NIR absorption of different liquids illuminated by NIR light from our phosphors, qualitative and quantitative analysis can be realized. These results suggest that the super-broad NIR luminescence of (Mg1−xLix)(Mg1−xScx)GeO4:Cr3+ has potential applications as light sources for nondestructive food analysis.