Preferred Label : order–disorder transition;
Detailed label : order-disorder transition;
IUPAC definition : A transition in which the degree of order of the system changes. Three principal types
of disordering transitions may be distinguished: (i) positional disordering in a solid,
(ii) orientational disordering which may be static or dynamic and (iii) disordering
associated with electronic and nuclear spin states. Examples: ol li The transition
of LiFeO sub 2 /sub , with a tetragonal unit cell, in which the Li sup class plus
/sup and Fe sup 3 /sup cations are perfectly ordered on crystallographically non-equivalent
octahedral sites to cubic LiFeO sub 2 /sub in which the Li sup class plus /sup
and Fe sup 3 /sup cations are distributed randomly over all the octahedral sites.
/li li The transition of orthorhombic KCN to cubic KCN in which the CN sup class
minus /sup ions become oriented in any of the eight [111] directions. /li li
A superconducting transition /li /ol ;
Origin ID : O04321;
See also
A transition in which the degree of order of the system changes. Three principal types
of disordering transitions may be distinguished: (i) positional disordering in a solid,
(ii) orientational disordering which may be static or dynamic and (iii) disordering
associated with electronic and nuclear spin states. Examples: ol li The transition
of LiFeO sub 2 /sub , with a tetragonal unit cell, in which the Li sup class plus
/sup and Fe sup 3 /sup cations are perfectly ordered on crystallographically non-equivalent
octahedral sites to cubic LiFeO sub 2 /sub in which the Li sup class plus /sup
and Fe sup 3 /sup cations are distributed randomly over all the octahedral sites.
/li li The transition of orthorhombic KCN to cubic KCN in which the CN sup class
minus /sup ions become oriented in any of the eight [111] directions. /li li
A superconducting transition /li /ol
