2014 Fiscal Year Final Research Report
Phase-separation and phase-control of the ordered state near the critical point by introducing the local inhomogeneity
| Project/Area Number |
24540383
|
|---|
| 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 | Sophia University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Renkei-kenkyūsha) |
AKAHOSHI Daisuke 東邦大学, 理学部, 准教授 (90407354)
AKAKI Mitsuru 大阪大学, 大学院理学研究科, 助教 (60610904)
|
|---|
| Project Period (FY) |
2012-04-01 – 2015-03-31
|
| Keywords | 不純物置換 / 磁性 / 誘電性 / 結晶 / 酸化物 / 相転移 / マルチフェロイック / 磁場 |
|---|
| Outline of Final Research Achievements |
We have investigated the Mn-site substitution effect in Nd0.45Sr0.55MnO3 crystal, which has an A-type layered antiferromagnetic (A-AFM) phase with the 3dx2-y2-type orbital-order. Substitution of Fe or Ga for Mn-site suppresses both the A-AFM order and competing ferromagnetic (FM) correlation, whereas Cr substitution suppresses only the A-AFM order but reactivates the underlying FM correlation via double-exchange mechanism. In Nd0.45Sr0.55Mn0.95Cr0.05O3, the A-AFM state with the orbital-order is changed into the orbital-disordered three-dimensional FM metallic state by applying magnetic field of 12 T, which is much smaller than that of the parent compound.
In addition, We have studied impurity-doping effect in multiferroic CaBa(Co1-xFex)4O7 with 0≦x≦0.25. The magnetization curve shows that the magnetic moment sharply rises at 64K for x = 0 and 54K for x = 0.005, while it does not change for 0.0156≦x. This result indicates that the ferrimagnetic state disappears above 0.0156.
|
| Free Research Field |
物質科学
|
