High-pressure studies of antiferromagnetic oxides with a delafossite-type triangular structure

具有铜铁矿型三角形结构的反铁磁氧化物的高压研究

• 批准号: 16540331
• 负责人: TAKAHASHI Hiroki
• 金额: $ 2.37万
• 依托单位: Nihon University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540331/
• 关键词: delafossite; triangular structure; magnetically frustrated sysytem; high pressure; antiferromagnetism; CuFeO_2; CuCrO_2; CuAlO_2; 超伝導

Since the high-Tc superconductor was discovered, great attension has been paid to low-dimensional transition metal oxides, from the view of strongly correlated electron systems. Some oxides with a delafossite-type structure have been attractive because of its low-dimensional triangular structure. CuFeO_2 has magnetic Fe^<3+> layers, which form a layered triangular lattice frustrated antiferromagnet, separated by nonmagnetic Cu^+ and O^<2-> layers. In a frustrated system, the magnetic phase transitions take place under a subtle balance of magnetic interactions. CuFeO_2 exhibits two successive antiferromagnetic transitions at 13 K(T_<N1>) and 9 K (T_<N2>). Another antiferromagnetic oxides, CuCrO_2 and transparent semiconductor, CuAlO_2 have also been investigated. Since impurity largely affects the antiferromagnetism of CuFeO_2, the pressure effect is expected to affect the magnetic state. In this study we have carried out magnetic susceptibility measurements on the antiferromagnetic tra … More nsition temperature of CuFeO_2 under high pressure and electrical resistivity measurements on CuCrO_2 and CuAlO_2 under high pressure. From the magnetic susceptibility measurements of CuFeO_2, the T_<N1> and T_<N2> decrease with pressure up to 0.7 GPa at a rate of -1K/GPa. If the T_<N1> and T_<N2> decrease linearly at a rate of -1 K/GPa, it disappears at 10 GPa. Then it is very interesting to perform high-pressure studies at more than 10 GPa, since a new magnetic phase can be expected at the pressure where the magnetic ordering state disappears, as observed in UGe_2. From the preliminary electrical resistivity measurements under high pressure, the resistivity decreases to 0.1 times value at 10 GPa. The susceptibility and electrical resisitivity measurements are in progress at_higher pressures. In the electrical resistivity measurements of CuCrO_2 and CuAlO_2 under high pressure, the resistivity decreases a little with increasing pressure. The resistivity measurements under much higher pressure are in progress. Less

自从高温超导体被发现以来，从强关联电子系统的角度出发，低维过渡金属氧化物一直受到人们的关注。一些具有铜铁矿型结构的氧化物由于其低维三角结构而具有吸引力。CuFeO_2中的Fe^&lt;3+&gt;层是磁性的，形成了层状三角晶格受抑反铁磁体，中间被Cu^+和O^层隔开<2->。在阻挫系统中，磁相变发生在磁相互作用的微妙平衡下。CuFeO_2在13 K（T_0<N1>）和9 K（T_0<N2>）时出现两个连续的反铁磁转变。对另一种反铁磁氧化物CuCrO_2和透明半导体CuAlO_2也进行了研究。由于杂质对CuFeO_2的反铁磁性有很大的影响，因此压力效应也会影响CuFeO_2的磁性。在这项研究中，我们进行了磁化率测量的反铁磁晶体， ...更多信息 高压下CuFeO_2的起始温度和高压下CuCrO_2和CuAlO_2的电阻率测量。从CuFeO_2的磁化率测量结果可以看出，在0.7GPa以下，T_<N1>和T_<N2>随压力的增加而减小，减小速率为-1K/GPa。如果T_<N1>和T_<N2>以-1K/GPa的速率线性下降，则在10 GPa时消失。在10 GPa以上的高压下进行研究是非常有趣的，因为在磁有序态消失的压力下可以预期新的磁相，正如在UGe_2中观察到的那样。从高压下的初步电阻率测量，电阻率降低到10 GPa时的0.1倍。磁化率和电阻率的测量是在更高的压力下进行的。在高压下测量CuCrO_2和CuAlO_2的电阻率时，电阻率随压力的增加略有下降。更高压力下的电阻率测量正在进行中。少

项目成果

Pressure effects on the superconductivity in Pr_2Ba_4Cu_7O_<15-δ> superconductor

压力对Pr_2Ba_4Cu_7O_<15-δ>超导体超导性的影响

• 发表时间: 2006
• 期刊: Proc.of LT24 (to be published)
• 作者: K.Fukuda;A.Kaeriyama;F.Ishikawa;Y.Yamada;A.Matsushita;H.Takahashi
• 通讯作者: H.Takahashi

Analysis of magnetic and structural phase transition behaviors of La1−xSrxCrO3 for preparation of phase diagram

• DOI: 10.1016/j.tca.2005.06.005
• 发表时间: 2005-09
• 期刊: Thermochimica Acta
• 影响因子: 3.5
• 作者: F. Nakamura;Y. Matsunaga;N. Ohba;K. Arai;H. Matsubara;Hiroki Takahashi;T. Hashimoto

Magnetic field effect on the pressure-induced superconducting state in the hole-doped two-leg ladder compound Sr_2Ca_<12>Cu_<24>O_<41>

磁场对空穴掺杂二足梯形化合物Sr_2Ca_<12>Cu_<24>O_<41>压力诱导超导态的影响

• 发表时间: 2005
• 期刊: Physical Review B 72
• 作者: T.Nakanishi;N.Motoyama;H.Mitamura;N.Takeshita;H.Takahashi;H.Eisaki;S.Uchida;N.Mori
• 通讯作者: N.Mori

マテリアルサイエンスにおける超高圧技術と高温超伝導研究

材料科学中的超高压技术与高温超导研究

• 发表时间: 2006
• 作者: K.Fukuda;A.Kaeriyama;F.Ishikawa;Y.Yamada;A.Matsushita;H.Takahashi;高橋博樹
• 通讯作者: 高橋博樹

Pressure effects on the superconductivity in Pr2Ba4Cu7O15-δ superconductor

压力对Pr2Ba4Cu7O15-δ超导体超导性的影响

• 期刊: Proc. of LT24,(2006) To be published
• 作者: K.Fukuda;A.Kaeriyama;F.Ishikawa;Y.Yamada;A.Matsushita;H.Takahashi
• 通讯作者: H.Takahashi