Prasad A, Hossain Z, Jeevan H S, Geibel C
Department of Physics, Indian Institute of Technology, Kanpur 208016, India.
J Phys Condens Matter. 2009 May 20;21(20):206003. doi: 10.1088/0953-8984/21/20/206003. Epub 2009 Apr 24.
We have grown single crystals of YbNiB(4) using a Ni(60)B(40) flux and determined the magnetic properties of this compound by means of magnetic susceptibility, specific heat and electrical resistivity measurement. Yb ions in YbNiB(4) are in a trivalent state and present a transition from a paramagnetic state to an antiferromagnetic (AF) state at T(N1) = 5.4 K and a further transition towards a second AF state at T(N2) = 4.0 K. Kondo type behavior in the resistivity and an enhanced Sommerfeld coefficient γ = 100 mJ mol(-1) K(-2) provide evidence for a significant Kondo interaction. A broad maximum in χ(T) at around 8 K, well above T(N1), suggests low-dimensional antiferromagnetic correlations. Both mechanisms lead to strong fluctuation in an extended temperature range above T(N1), up to the characteristic energy of this system, which was estimated to be T(4f) = 16 K from an analysis of the entropy.
我们使用Ni(60)B(40)助熔剂生长出了YbNiB₄单晶，并通过磁化率、比热和电阻率测量确定了该化合物的磁性。YbNiB₄中的Yb离子处于三价态，在TN₁ = 5.4 K时从顺磁态转变为反铁磁（AF）态，并在TN₂ = 4.0 K时进一步转变为第二个AF态。电阻率中的近藤型行为以及增强的索末菲系数γ = 100 mJ mol⁻¹ K⁻²为显著的近藤相互作用提供了证据。χ(T)在约8 K处有一个宽峰，远高于TN₁，表明存在低维反铁磁关联。这两种机制都导致在TN₁以上的扩展温度范围内出现强烈波动，直至该系统的特征能量，通过对熵的分析估计该特征能量为T(4f) = 16 K。
