scholarly journals Spectrochemical and thermal behaviours of the 2,4- and 3,4-dimethoxybenzoates of rare earth elements

2000 ◽  
Vol 65 (11) ◽  
pp. 789-798 ◽  
Author(s):  
Wieslawa Ferenc ◽  
Agnieszka Walków-Dziewulska

The physicochemical properties and thermal stability in air of the 2,4- and 3,4-dimethoxybenzoates of rare earth elements were compared in order to observe the influence of the position of the -OCH3 substituent on their thermal stability. The complexes of these two series are crystalline, hydrated or anhydrous salts with colours typical of trivalent rare earth ions. The carboxylate group is a bidentate, chelating ligand. The thermal stability of the 2,4- and 3,4-dimethoxybenzoates of the lanthanide elements was studied in the temperature range 273-1173 K. The positions of methoxy- groups in the benzene ring influence the number of crystallization water molecules in the complexes and their thermal stability, which is connected with the varying influence of inductive and mesomeric effects of the -OCH3 substituent on the electron density in the benzene ring.

2020 ◽  
Vol 22 (28) ◽  
pp. 16294-16300
Author(s):  
Xiuxia Yang ◽  
Lei Zhao ◽  
Zhichao Liu ◽  
Shuyu Tian ◽  
Hao Zhang ◽  
...  

Manipulating the local environment of CAS by substitution of Al3+–Y3+ for Si4+–Ca2+ to achieve more stability in the structure of CYA.


2010 ◽  
Vol 63 (6) ◽  
pp. 661-664 ◽  
Author(s):  
Lingwei Zeng ◽  
Daqin Chen ◽  
Lifeng Cui ◽  
Feng Huang ◽  
Yuansheng Wang

1993 ◽  
Vol 161 ◽  
pp. 77-80 ◽  
Author(s):  
M.R. Shahriari ◽  
T. Iqbal ◽  
P. Hajcak ◽  
G.H. Sigel

2011 ◽  
Vol 688 ◽  
pp. 426-430 ◽  
Author(s):  
Yan Fang Wang ◽  
Li Li ◽  
Chuan Sun ◽  
Qing Long Lu ◽  
Zhi Qiang Shi

The rare earth elements (RE= Y, Sm, La, Ce) were used as alloying materials in Cu50Zr45Al5BMG, and their influences on the glass-forming ability and thermal stability were studied in this paper. All the samples remained in full metallic glass state with minor additions of Y, Sm and La. Increasing the amount of RE additions, the Cu10Zr7and Zr2Cu phases precipitated and glass transition temperatureTgand crystallization temperatureTxsignificantly decreased. The reduced glass transition temperature Trg=Tg/Tlranged from 0.592 to 0.611 and the γ parameter ranged from 0.393 to 0.409.


1980 ◽  
Vol 35 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Jorma Hölsä ◽  
Markku Leskelä ◽  
Lauri Niinistö

1986 ◽  
Vol 41 (6) ◽  
pp. 866-870 ◽  
Author(s):  
H.-D. Autenrieth ◽  
S. Kemmler-Sack

By activation of the new host lattices Ba2La2B2+Te2O12 (B = Zn, Mg) with trivalent rare earth ions Ln3+ = Pr. Sm, Eu, Tb, Dy, Ho, Tm an emission in the visible region is observed. The influence of the electronic structure and concentration on the relative emission efficiency as well as the host lattice participation in the energy transfer processes are discussed.


2016 ◽  
Vol 40 (7) ◽  
pp. 6214-6227 ◽  
Author(s):  
Gattupalli Manikya Rao ◽  
G. Seeta Rama Raju ◽  
Sk. Khaja Hussain ◽  
E. Pavitra ◽  
P. S. V. Subba Rao ◽  
...  

Sr2Gd8(SiO4)6O2 is an excellent host lattice for tunable emissions via the white-light region when co-doped with suitable trivalent rare-earth ions.


2003 ◽  
Vol 102-103 ◽  
pp. 216-219 ◽  
Author(s):  
E. Cavalli ◽  
A. Speghini ◽  
M. Bettinelli ◽  
M.O. Ramírez ◽  
J.J. Romero ◽  
...  

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