Magnetic and transport properties of the narrow-gap semiconductor Yb5Si4

International Conference on Strongly Correlated Electron Systems 2014

Kosaka, Masashi^1 ; Ottomo, Shingo^1 ; Machida, Ayumi^1 ; Kirigane, Tomoyuki^1 ; Numakura, Ryosuke^1 ; Katano, Susumu^1 ; Michimura, Shinji^1,2

Graduate School of Science and Engineering, Saitama University, Saitama

338-8570, Japan^1

Research and Development Bureau, Saitama University, Saitama

338-8570, Japan^2

关键词: Antiferromagnetic transition;    Crystallographic sites;    Effective magnetic moments;    Electrical resistivity measurements;    Magnetic and transport properties;    Narrow-gap semiconductors;    Semiconducting behavior;    Temperature dependence;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012092/pdf
DOI  :  10.1088/1742-6596/592/1/012092

来源: IOP

【 摘 要 】

We report the synthesis and basic properties of the binary compound Yb5Si4. In this compound, Yb ions occupy three different crystallographic sites, the multiplicity of which is represented by Yb1 : Yb2 : Yb3 =1:2:2. The estimated effective magnetic moment and magnetic entropy can be explained by the proportion of Yb valence states, Yb3+: Yb2+=2:3. This result suggests the possibility that Yb3+ions occupy either Yb2 or Yb3 site. Yb5Si4undergoes an antiferromagnetic transition at TN=1.7 K. The extended high temperature tail in the temperature dependence of the specific heat just above TNhas been observed. Yb5Si4also exhibits the broad maximum peak around 2.3 K in the magnetic susceptibility, corresponding to the specific heat anomaly. We propose that these anomalies are possible to originate from magnetic fluctuations caused by low-dimensional Yb3+networks. Electrical resistivity measurements on Yb5Si4reveal semiconducting behavior at all temperatures. The small energy gap Δ= 430 K has been obtained at room temperature estimated by the thermal activation model. The energy gap gradually decreases with decreasing temperature, and reaches about 3 K at low temperatures.