TY - JOUR
T1 - Partial disordered phase of Ising spin system in distorted triangular lattice RbCoBr3
AU - Nishiwaki, Yoichi
AU - Nakamura, Tota
AU - Oosawa, Akira
AU - Kakurai, Kazuhisa
AU - Todoroki, Norikazu
AU - Igawa, Naoki
AU - Ishii, Yoshinobu
AU - Kato, Tetsuya
PY - 2008/10
Y1 - 2008/10
N2 - Powder and single-crystal neutron diffraction measurements were performed on RbCoBr3. The magnetic phase transitions of this compound are well explained by the Ising spin model for a distorted triangular lattice. Magnetic peaks of powder diffraction patterns at 34 and 20K closely fit a partial disordered phase and a ferrimagnetic phase, respectively. The temperature dependences of the (h, h, 1) scan profile and magnetic Bragg peak heights at (1, 1, 1), (1/3, 1/3, 1), and (2/3, 2/3, 1) were measured for a single-crystal sample. We conclude that the ferrimagnetic phase only exists below 30.5 K. The partial disordered phase is identified between 30.5 (= TN2) and 37.2K (= TN1). We found a characteristic linear increase in the (1, 1, 1) peak height below TN2 with decreasing temperature. These results show that a lattice distortion couples to the spin system. Numerical simulations are also performed to estimate magnetic interaction parameters.
AB - Powder and single-crystal neutron diffraction measurements were performed on RbCoBr3. The magnetic phase transitions of this compound are well explained by the Ising spin model for a distorted triangular lattice. Magnetic peaks of powder diffraction patterns at 34 and 20K closely fit a partial disordered phase and a ferrimagnetic phase, respectively. The temperature dependences of the (h, h, 1) scan profile and magnetic Bragg peak heights at (1, 1, 1), (1/3, 1/3, 1), and (2/3, 2/3, 1) were measured for a single-crystal sample. We conclude that the ferrimagnetic phase only exists below 30.5 K. The partial disordered phase is identified between 30.5 (= TN2) and 37.2K (= TN1). We found a characteristic linear increase in the (1, 1, 1) peak height below TN2 with decreasing temperature. These results show that a lattice distortion couples to the spin system. Numerical simulations are also performed to estimate magnetic interaction parameters.
KW - Frustration
KW - Ising spin
KW - Lattice distortion
KW - Neutron diffraction
KW - Partial disordered phase
KW - RbCoBr
KW - Triangular lattice
UR - http://www.scopus.com/inward/record.url?scp=54349092379&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=54349092379&partnerID=8YFLogxK
U2 - 10.1143/JPSJ.77.104703
DO - 10.1143/JPSJ.77.104703
M3 - Article
AN - SCOPUS:54349092379
VL - 77
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 10
M1 - 104703
ER -