Fluctuation Effects on the Quadrupolar Ordering in Magnetic Field

概要

論文の詳細を見る
Effects of naagnetic field on the qtradrtrpolar ordering are investigated with incltusion of flucttration of order pararneters. For tlae sizaaplest rnodel with the nearest-neighbor quadrupoJarinteractiora, the transition tentperattzre and the specific heat are derived by the trse of the re-centJy proposed effectix'e meditntn theory, It is shown that ttaagnetic field H has two cotmpetingeffects on the quadrtrpolar ordering; one is to encotrrage the ordering by suppressing the fJucttra-tion 2Yll1OI1g different coutaponents of order paranaeters, and tlae other is to block the ordering as inantiferrozaaagnets. The fornner is fotrnd to be of order H' and the latter of order H'. Hence theflvrcttration is suppressed for weak fields, and the transition tenaaperattrre increases with rnagneticfield. The flucttration eff'ect is so strong that the entropy released at the quadrupolar orderingis only about a quarter of the full value In 4 even xvithotzt the Kondo effect.
社団法人日本物理学会の論文
1998-07-15