Investigation of Mn, Fe, and Ni Incorporation in CeCo2Al8

Single crystals of CeCo2–xMxAl8 (M =
Mn, Fe, Ni; 0 ≤ x < 1) were grown and characterized
by X-ray diffraction and magnetic susceptibility. The unit cell volumes
of Mn-doped compounds increase and those of Ni-doped compounds decrease
with increasing dopant concentration. All samples display a magnetic
ordering near 6 K with magnetic moments of the analogues ranging from
2.61 to 2.81 μB/mol Ce and slightly higher than Ce3+ only magnetic moment. The unit cell volumes of Fe-doped
compounds also increase with increasing Fe concentration. However,
the cell volume of CeCo2–xFexAl8 decreases for x = 1.00 and is not Curie–Weiss possibly because of valence
fluctuation.

CeCo2–xMxAl8 (M代表Mn、Fe、Ni；0 ≤ x < 1)的单晶通过X射线衍射和磁化率进行了生长与表征。随着掺杂浓度的上升，Mn掺杂化合物的晶胞体积增大，而Ni掺杂化合物的晶胞体积则减小。所有样品在接近6 K的温度下展现出磁序，其类比对磁矩介于2.61至2.81 μB/mol Ce之间，且略高于Ce3+的单一磁矩。Fe掺杂化合物的晶胞体积亦随Fe浓度的增加而增大。然而，当x = 1.00时，CeCo2–xFexAl8的晶胞体积减小，且不呈现居里-外斯行为，这或许是由于价态波动所致。