Center for Correlated Matter and Department of Physics, Zhejiang University, Hangzhou, Zhejiang 310027, People's Republic of China.
J Phys Condens Matter. 2014 Jan 29;26(4):045601. doi: 10.1088/0953-8984/26/4/045601. Epub 2013 Dec 20.
We report the successful synthesis of the polycrystalline compounds CePd2As2-xPx (0 ≤ x ≤ 2) and their physical properties by measuring transport, magnetic and thermodynamic behaviors as a function of temperature and/or magnetic field. Powder x-ray diffraction indicates that CePd2As2-xPx crystallizes in the ThCr2Si2-type tetragonal structure. CePd2As2 exhibits a moderate Sommerfeld coefficient of γ ≈ 88 mJ mol(-1) K(-2), and undergoes an antiferromagnetic (AFM) transition at the Néel temperature TN ≈ 15 K. Upon substituting As with P, the TN is nearly unchanged up to x ≃ 0.6, while a ferromagnetic (FM) transition develops below TN for x ≃ 0.4. The Curie temperature TC increases with increasing x and eventually merges with the AFM transition at x ≃ 0.6. With further increase of x, the system follows typical FM behaviors and its TC monotonically increases and reaches TC ≈ 28 K in CePd2P2. Moreover, a metamagnetic transition is observed in the As-rich samples, but vanishes for x ≥ 0.4. Such a tunable magnetic ground state may provide an opportunity to explore the possible quantum critical behavior in CePd2As2-xPx.
我们成功合成了多晶化合物 CePd2As2-xPx(0 ≤ x ≤ 2),并通过测量其输运、磁和热力学性质随温度和/或磁场的变化来研究其物理性质。粉末 X 射线衍射表明 CePd2As2-xPx 结晶为 ThCr2Si2 型四方结构。CePd2As2 表现出中等的 Sommerfeld 系数 γ ≈ 88 mJ mol(-1) K(-2),并在奈尔温度 TN ≈ 15 K 处发生反铁磁(AFM)转变。用 P 取代 As 时,直到 x ≃ 0.6,TN 几乎不变,而在 x ≃ 0.4 以下会发生铁磁(FM)转变。居里温度 TC 随 x 的增加而增加,最终在 x ≃ 0.6 处与 AFM 转变合并。进一步增加 x,系统呈现出典型的 FM 行为,其 TC 单调增加,并在 CePd2P2 中达到 TC ≈ 28 K。此外,在富 As 样品中观察到了顺磁转变,但在 x ≥ 0.4 时消失。这种可调谐的磁基态可能为探索 CePd2As2-xPx 中可能的量子临界行为提供了机会。