| Project/Area Number |
15K05150
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Condensed matter physics II
|
|---|
| Research Institution | National Institute for Materials Science |
|---|
Principal Investigator |
Hase Masashi 国立研究開発法人物質・材料研究機構, 先端材料解析研究拠点, グループリーダー (40281654)
|
|---|
| Research Collaborator |
Kohno Masanori
|
|---|
| Project Period (FY) |
2015-04-01 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
|
|---|
| Keywords | 反強磁性交替鎖 / 量子相転移 / 混晶 / スピンギャップ / 中性子非弾性散乱 / 磁化 |
|---|
| Outline of Final Research Achievements |
We investigated the magnetism of spin-3/2 antiferromagnetic alternating chain compounds RCrGeO5 (R = Ho, Er or Nd) and NdCrTiO5 using magnetization and neutron-scattering measurements. The compounds as well as already known R = Y or Sm compounds have a strongly dimerized ground state. We were not able to find a compound with a weakly dimerized ground state.
We also studied antiferromagnetic spin cluster compounds. We found a small magnetic moment in CuInVO5, reduction of the magnetic moment by quantum fluctuation in FeVMoO7 in spite of spin-5/2, and unstable ordered state in 0 T in Rb2Ni2Mo3O12 like an order in the vicinity of a quantum critical point.
|
| Academic Significance and Societal Importance of the Research Achievements |
RCrGeO5 (R = Y, Sm, Ho, Er, Nd)とNdCrTiO5の研究の結果、2つのCrスピン間に働く交換相互作用の大きさがCr-Cr距離にとても強く依存することが分かった。Cr-Cr距離が少しでも長くなると、交換相互作用が急激に小さくなるため、これらの物質の2種類の交換相互作用の大きさが大きく異なり、ボンド交替が弱いダイマー基底状態が実現できなかった。
量子臨界点近傍の秩序は通常、圧力や磁場を加えて初めて現れる。Rb2Ni2Mo3O12では、大気圧下のゼロ磁場でも、量子臨界点近傍の秩序が可能なことが分かった。
|
