Synthesis, structure, and magnetic properties of the two-dimensional quantum antiferromagnets(CuBr)A2B3O10(A=Ca, Sr, Ba, Pb;B=Nb, Ta) with the 1/3 magnetization plateau

Autor: Adam A. Aczel, Travis Williams, Kazuyoshi Yoshimura, Yoshitami Ajiro, Koichi Kindo, Yasutomo J. Uemura, Yoshihiro Tsujimoto, Jeremy P. Carlo, Hiroshi Kageyama, Yoichi Baba, Yasuo Narumi, Masakazu Nishi, Atsushi Kitada, Y. Ueda, Tatsuo Goko, Takafumi Yamamoto, Graeme Luke
Rok vydání: 2008
Předmět:
Zdroj: Physical Review B. 78
ISSN: 1550-235X
1098-0121
DOI: 10.1103/physrevb.78.214410
Popis: A 1/3 magnetization plateau was recently observed in the layered perovskite $(\text{CuBr}){\text{Sr}}_{2}{\text{Nb}}_{3}{\text{O}}_{10}$ with $S=1/2$ CuBr layers. In order to control the cell size and thus exchange parameters, we have prepared an isostructural series of $(\text{CuBr}){A}_{2}{B}_{3}{\text{O}}_{10}$ ($A=\text{Ca}$, Sr, Ba, Pb; $B=\text{Nb}$, Ta) and investigated the magnetic properties. We found that the stability of the 1/3 magnetization plateau is systematically tunable by the lattice parameter $a$. A substantial role played by the superexchange pathway via $B{\text{O}}_{6}\text{\ensuremath{-}}B{\text{O}}_{6}$ in the magnetic properties is suggested in addition to that via Br. Specific heat and muon spin relaxation measurements show that the appearance of the plateau phase is accompanied by successive phase transitions in low fields---the first one is possibly a structural transition and the second one is a magnetic transition. Frustration may induce the structural distortion and stabilize the 1/3 plateau phase.
Databáze: OpenAIRE