Magnetic Properties of a Quantum Ferrimagnet: NiCu(pba)(D_2O)_3 . 2D_2O

Masayuki Hagiwara; Kazuhiko Minami; Yasuo Narumi; Keiji Tatani; Koichi Kindo

doi:10.1143/JPSJ.67.2209

paper

Magnetic Properties of a Quantum Ferrimagnet: NiCu(pba)(D_2O)_3 . 2D_2O

arXiv:cond-mat/9807348 · doi:10.1143/JPSJ.67.2209

Abstract

We report the results of magnetic measurements on a powder sample of NiCu(pba)(D_2O)_3 \cdot 2D_2O $(p ba = 1, 3 - p r o p y l e n e bi s (o x ama t o)) w hi c hi so n eo f t h e p r o t o t y p i c a l e x am pl eso f an$ S $= 1/2 an d 1 f er r ima g n e t i cc hain . S u sce pt ibi l i t y ($ χ $) s h o w s am o n o t o n o u s in cr e a se w i t h d ecr e a s in g t e m p er a t u r e (T) an d r e a c h es ama x im u ma t ab o u t 7 K . I n t h e pl o t o f$ χT $v er s u s$ T $, t h ee x p er im e n t a l d a t a e x hibi t ab r o a d minim u man d a r e f i tt o t h e$ χT $c u r v ec a l c u l a t e df or t h e f er r ima g n e t i cH e i se nb er g c hain co m p ose d o f S = 1/2 an d 1. F r o m t hi s f i t, w e ha v ee v a l u a t e d t h e n e a r es t - n e i g hb or e x c han g eco n s t an t$ J/k_B=121 K $, t h e g - v a l u eso f N i$ ^{2+} $an d C u$ ^{2+} $,$ g_{Ni} $= 2.22 an d$ g_{Cu} $= 2.09, r es p ec t i v e l y . A ppl i e d e x t er na l f i e l dd e p e n d e n ceo f$ χT$ at low temperatures is reproduced fairly well by the calculation for the same ferrimagnetic model.

7pages, 4 postscript figures, usues REVTEX. appear in J. Phys. Soc. Jpn vol 67 No.7 (1998)