Random magnetic fields and tricritical behavior of diamagnetically dilute antiferromagnets (Ni1-xMgx)O
Men'shikov A. Z. , Dorofeev Yu. A. , Klimenko A. G. , Mironova N. A.
The solid solutions (Nix _ xMgx)О are used as an example to show, for the first time, that a random substitution of magnesium ions in the nickel sublattice is manifested as a random-magnetic-field effect. This effect first causes a local magnetic disorder and then leads to a complete disruption of the long-range magnetic order in a topologically infinite antiferromagnetic cluster. A region of tricritical behavior and a cluster spin glass appears.