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Synthesis of 10 nm β‐NaYF4:Yb,Er/NaYF4 Core/Shell Upconversion Nanocrystals with 5 nm Particle Cores 下载免费PDF全文
Thorben Rinkel Athira Naduviledathu Raj Simon Dühnen Prof. Dr. Markus Haase 《Angewandte Chemie (International ed. in English)》2016,55(3):1164-1167
A new method is presented for preparing gram amounts of very small core/shell upconversion nanocrystals without additional codoping of the particles. First, ca. 5 nm β‐NaYF4:Yb,Er core particles are formed by the reaction of sodium oleate, rare‐earth oleate, and ammonium fluoride, thereby making use of the fact that a high ratio of sodium to rare‐earth ions promotes the nucleation of a large number of β‐phase seeds. Thereafter, a 2 nm thick NaYF4 shell is formed by using 3–4 nm particles of α‐NaYF4 as a single‐source precursor for the β‐phase shell material. In contrast to the core particles, however, these α‐phase particles are prepared with a low ratio of sodium to rare‐earth ions, which efficiently suppresses an undesired nucleation of β‐NaYF4 particles during shell growth. 相似文献
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MohammedIbrahim Shukoor Filipe Natalio Nadine Metz Natalie Glube MuhammadNawaz Tahir HelenAnnal Therese Vadim Ksenofontov Patrick Theato Peter Langguth Jean‐Paul Boissel HeinzC. Schrder WernerE.G. Müller Wolfgang Tremel 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2008,120(25):4826-4830
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