A Study of CDW state in alkali metals

碱金属中CDW态的研究

• 批准号: 05452053
• 负责人: SUZUKI Haruhiko
• 金额: $ 3.78万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05452053/
• 关键词: CDW; alkali metals; Dilution Refrigerator; SOR; 超低温; 相転移; 結晶変態

1.Preparation : Since the alkali metals are easily oxiclized and also easily react with other metals, quartz and chemical solvents, we must be careful to treat the alkali metals. We made a rather large glove box inside which we can glow the single crystals of K metal and seal the crystal inside the quartz ampule together with He gas.2.SOR-Xray : At the Photon Factory of KEK in Tsukuba, We measured the x-ray at low temperatures by using a 3He-4He dilution refrigerator. The lowest temperature of the measurements was 75 mK.Compared the Laue spots measured at the lowest temperature with one measured at the liquid Nitrogen temperature, some spots with some indexes has the satellite and split into two or more spots at the lowest temperature. At present we cannot conclude that these phenomena are resultant of the CDW transition.3.Magnetic susceptibility : We measured the temperature dependence of the magnetic susceptibility of K metal by using a SQUID magnetometer between 1.8 and 300K.Above 20 K the magnetic susceptibility is almost temperature independent, but below 20 K it starts to decrease with decreasing temperature. And at about 10 K it decreasing more rapidly. At present we do not know if this temperature dependence of the magnetic susceptibility is due to the forming the electronic energy gap at the Fermi energy by CDW transition.In conclusion our experimental results suggest the possibility of CDW state in K metal.

1.制备：由于碱金属容易氧化，也容易与其他金属、石英和化学溶剂反应，因此必须小心处理碱金属。我们制作了一个相当大的手套盒，在里面我们可以发光K金属的单晶，并将晶体与He气体一起密封在石英瓶中。2.SOR-X光：在筑波的KEK光子工厂，我们用3He-4He稀释式制冷机测量了低温X射线。测量的最低温度为75mK，与在液氮温度下测量的Laue斑点相比，一些具有某些指标的斑点在最低温度下存在卫星并分裂成两个或更多个斑点。3.磁化率：我们用SQUID磁强计在1.8-300K范围内测量了K金属的磁化率随温度的变化。在20K时，磁化率几乎与温度无关，但在20K以下，随着温度的降低，磁化率开始下降。在10K左右，降温速度更快。目前，我们还不知道这种磁化率的温度依赖性是否是由于在费米能区通过CDW跃迁形成电子能隙所致。总之，我们的实验结果表明K金属中存在CDW态的可能性。

项目成果

T.Nakajima: "Evidence for the Jahn-Teller Distortios of Cs_2NaHoCl_6 at 150mk" J.Low Temp.Physics. 96. 47-59 (1994)

T.Nakajima：“150mk 时 Cs_2NaHoCl_6 的 Jahn-Teller 扭曲的证据”J.Low Temp.Physics。

中島哲夫: "Evidence for the Jahn-Teller Distortion of Cs_2NaHoCl_6 at 150mK" J.Low Temp.Phys.96. (1994)

Tetsuo Nakajima：“150mK 下 Cs_2NaHoCl_6 的 Jahn-Teller 畸变的证据”J.Low Temp.Phys.96 (1994)。

H.Suzuki: "Nuclear Spin Order of Sc Metal" Physica B. vol.194-196. 249-250 (1994)

H.Suzuki：“Sc 金属的核自旋序”Physica B. vol.194-196。

H.Suzuki: "Magnetic Properties of Ba2CU3-xMxO4Cl2 (M=Ni, Zn)" Physica B. vol.194-196. 2275-2276 (1994)

H.Suzuki：“Ba2CU3-xMxO4Cl2 (M=Ni, Zn) 的磁性”Physica B. vol.194-196。

H.Suzuki: "Magnetic Properties of Ba_2Cu_<3-x>M_xO_4Cl_2(M=Ni,Zu)" Physica B. 194-196. 2275-2276 (1994)

H.Suzuki：“Ba_2Cu_<3-x>M_xO_4Cl_2(M=Ni,Zu) 的磁性”Physica B. 194-196。