讨论了适应高压实验需要的交流量热技术的最新发展。用Bridgman型压室和金刚石对顶压室在0.1 K < T ~ 1.5 K的温度范围内半定量测量比热是可能< 10 K. The pressure transmitting medium used to ensure good pressure conditions determines to a great extent via its thermal conductivity the operating frequency and thus the accessible temperature range. Investigations with different pressure transmitting media for T >的,固体He的截止频率比滑石的高得多。低于1 K和压力高于10 GPa的实验清楚地表明,可以测量比热的线性温度系数的压力依赖性。这是在定性协议的相关数量获得准同时通过电阻率测量相同的样品。
英文摘要:
Recent developments of the AC-calorimetric technique adapted for the needs of high pressure experiments are discussed. A semi-quantitative measurement of the specific heat with a Bridgman-type of pressure cell as well as a diamond anvil cell is possible in the temperature range 0.1 K < T < 10 K. The pressure transmitting medium used to ensure good pressure conditions determines to a great extent via its thermal conductivity the operating frequency and thus the accessible temperature range. Investigations with different pressure transmitting media for T > 1.5 K reveal for solid He a cut-off frequency which is considerably higher than for steatite. Experiments below 1 K and pressures above 10 GPa clearly show that the pressure dependence of the linear temperature coefficient of the specific heat can be measured. It is in qualitative agreement to a related quantity obtained quasi-simultaneously by electrical resistivity measurements on the same sample.
Pressure phase diagram and quantum criticality of CePt2In7 single crystals
本文报道了CePt_2In_7单晶的温度-压力(T-P)相图,特别是反铁磁序的压力演化和超导电性的出现,并在近流体静力学环境下用电阻率和交流量热法进行了研究。与多晶超导体相比,体超导与反铁磁共存的压力范围要窄得多。在CePt 2 In 7中也观察到了织构超导性和局域量子临界性的可能存在,表现出与CeRhIn 5的显著相似性。
Spectrum and low-temperature bulk properties of triangular quantum spin liquid candidate NaYbSe$_2$
Los Alamos National Laboratory(洛斯阿拉莫斯国家实验室);National High Magnetic Field Laboratory, Los Alamos National Laboratory(洛斯阿拉莫斯国家实验室国家高磁场实验室);University of California, Berkeley(加州大学伯克利分校);University of Tennessee, Knoxville(田纳西大学诺克斯维尔分校);National High Magnetic Field Laboratory, Florida State University(佛罗里达州立大学国家高磁场实验室);Oak Ridge National Laboratory(橡树岭国家实验室);Lanzhou University(兰州大学);Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所);Shanghai Jiao Tong University(上海交通大学);University of Florida(佛罗里达大学)
High-pressure study of the ground- and superconducting-state properties of CeAu$_2$Si$_2$
新的重费米子超导体CeAu $_2$ Si $_2$的压力-温度-相图与以前研究的结果有明显的不同。事实上,超导性不是在边缘出现,而是在磁相的深处出现。在这种情况下,我们进行了交流量热法,电阻率和热电功率测量的CeAu $_2$ Si $_2$ -单晶在高压下。该实验的主要创新之处是观察到一条新的过渡线,推测是反铁磁相内$T_{\mathrm{M}}^{\mathrm{mod}}$处的磁结构重排,以及与超导性相关的电阻率量子临界行为的发生。强的非费米液体的行为被观察到周围的超导电性的最大值和增强的散射率被观察到接近超导电性的出现和最大值。有趣的是,$T_{\mathrm{M}}^{\mathrm{mod}}$几乎与超导转变的开始在一个广泛的压力范围内,在那里神秘的Tc增加与磁性的加强。比较了CeAu $_2$ Si $_2$及其母体化合物CeCu $_2$ Si $_2$和CeCu $_2$ Ge $_2$随单胞体积变化的特征,提出了价键交叉的临界涨落在超导配对机制中起着至关重要的作用。我们的研究揭示了磁性的新的有趣特征,并说明了磁性,量子临界性和超导性之间的复杂相互作用。