scholarly journals Negative thermal expansion in CdSe quasi-two-dimensional nanoplatelets

2019 ◽  
Vol 100 (3) ◽  
Author(s):  
Alexander I. Lebedev
2021 ◽  
Vol 103 (9) ◽  
Author(s):  
J. L. Niedziela ◽  
L. D. Sanjeewa ◽  
A. A. Podlesnyak ◽  
L. DeBeer-Schmitt ◽  
S. J. Kuhn ◽  
...  

2021 ◽  
Author(s):  
Jinsheng Liao ◽  
Minghua Wang ◽  
Fulin Lin ◽  
Zhuo Han ◽  
Datao Tu ◽  
...  

Abstract Lanthanide (Ln3+)-doped phosphors generally suffer from thermal quenching, in which their photoluminescence (PL) intensities decrease at the higher temperature. Herein, we report a class of unique two-dimensional negative-thermal-expansion phosphor of Sc2(MoO4)3:Yb/Er. By virtue of the reduced distances between sensitizers and emitters as well as confined energy migration with increasing the temperature, a 45-fold enhancement of green upconversion (UC) luminescence and a 450-fold enhancement of near-infrared downshifting (DS) luminescence of Er3+ are achieved from 25 to 500 ˚C. The thermally boosted UC and DS luminescence mechanism is systematically investigated through in situ temperature-dependent Raman spectroscopy, synchrotron X-ray diffraction and PL dynamics. Moreover, the luminescence lifetime of 4I11/2 of Er3+ in Sc2(MoO4)3:Yb/Er displays a strong temperature dependence, enabling ratiometric thermometry with the highest relative sensitivity of 13.4%/K at 298 K. These findings may gain a vital insight into the design of negative-thermal-expansion Ln3+-doped phosphors for versatile applications.


2003 ◽  
Vol 125 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Hiroshi Negishi ◽  
Yoshihiro Kuroiwa ◽  
Hiroyasu Akamine ◽  
Shinobu Aoyagi ◽  
Akikatsu Sawada ◽  
...  

Author(s):  
Joseph N Grima ◽  
Pierre S Farrugia ◽  
Ruben Gatt ◽  
Victor Zammit

We analyse the anisotropic thermal expansion properties of a two-dimensional structurally rigid construct made from rods of different materials connected together through hinges to form triangular units. In particular, we show that this system may be made to exhibit negative thermal expansion coefficients along certain directions or thermal expansion coefficients that are even more positive than any of the component materials. The end product is a multifunctional system with tunable thermal properties that can be tailor-made for particular practical applications.


2016 ◽  
Vol 94 (21) ◽  
Author(s):  
Sahan U. Handunkanda ◽  
Connor A. Occhialini ◽  
Ayman H. Said ◽  
Jason N. Hancock

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