Premium
Influence of the electron concentration on the superconducting properties of the spinel system Li 1‐ y Ti 2 O 4
Author(s) -
Rygula M.,
KemmlerSack S.,
Nissel T.,
Hübener R. P.
Publication year - 1993
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.19935050803
Subject(s) - spinel , superconductivity , materials science , crystal structure , analytical chemistry (journal) , extraction (chemistry) , electron , ion , lattice (music) , solid solution , transition temperature , oxygen , crystallography , condensed matter physics , physics , chemistry , metallurgy , chromatography , quantum mechanics , acoustics
In the spinel system Li 1‐ y Ti 2 O 4 the Li content was reduced by oxidative extraction by means of a solution of I 2 as well as Br 2 in CH 3 CN or by oxygen. The extraction is associated with a transition of Ti 3+ to Ti 4+ : the system is Li 1‐ y Ti 3+ 1‐ y Ti 4+ 1+ y O 4 . Consequently, with increasing y the charge carrier concentration decreases from the starting value of 0.5 electrons/Ti ion for LiTi 2 O 4 . The extraction proceeds in two steps. At the beginning, the Ti 2 O 4 framework remains intact and the transition to superconductivity increases with decreasing charge carrier concentration to a maximal value of 13.2 K. Separated by a two‐phase region for medium extraction levels for higher y values, a Li depleted material of approximate composition Li 0.3 Ti 2 O 4 is obtained. The crystal structure of Li 0.3 Ti 2 O 4 can be deduced from the original spinel lattice by a partial Ti migration from 16 d to 16 c and 8 a sites (space group Fd3m). Consequently, the Ti 2 O 4 framework of Li 0.3 Ti 2 O 4 is disconnected and the material is no longer superconducting.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom