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Single crystals of Ln2Fe4- xCo xSb5- yBi y (Ln = La, Ce; 0 ≤ x < 0.5; 0 ≤ y ≤ 0.2) were grown using Bi flux and self-flux methods. The compounds adopt the La2Fe4Sb5 structure type with tetragonal space group I4/ mmm. The La2Fe4Sb5 structure type is comprised of rare earth atoms capping square Sb nets in a square antiprismatic fashion and two transition-metal networks forming a PbO-type layer with Sb and transition-metal isosceles triangles. Substituting Co into the transition-metal sublattice results in a decrease in the transition temperature and reduced frustration, indicative of a transition from localized to itinerant behavior. In this manuscript, we demonstrated that Bi can be used as an alternate flux to grow single crystals of antimonides. Even with the incorporation of Bi into the Sb square net, the magnetic properties are not significantly affected. In addition, we have shown that the incorporation of Co into the Fe triangular sublattice leads to an itinerant magnetic system.

Single crystals of the ternary Pr3Co2+xGe7 and Ln3Co2+xGe7–ySny (Ln = Pr, Nd, Sm) adopting a disordered version of the La3Co2Sn7 structure type have been prepared via flux-growth methods and characterized by single crystal X-ray diffraction. The structure consists of two lanthanide crystallographic sites with one occupying a cuboctahedral coordination environment and a second in a trigonal prismatic environment. The structure can also be described as an intergrowth of AuCu3 and CeNiSi2 structure types, and the stability of the germanide analogues requires Sn incorporation and Co site preferences. Magnetic properties of the Pr3Co2+xGe7–ySny series are highlighted with the Sn-substituted Pr3Co2.514(5)Ge6.66(7)Sn0.360(2) orders magnetically near 5.8 K, while the germanide Pr3Co2.3376(5)Ge7.056(7) exhibits magnetic transitions at 5.3 and 9.3 K, arising from the magnetic sublattices with field-dependent magnetization revealing three metamagnetic transitions at 0.46, 0.80, and 2.1 T.

Single crystals of Ln6MnSb15 (Ln=La, Ce), Ln6Mn1−xZnxSb15 (x~0.5), and Ln6ZnSb15 (Ln=La–Pr) have been successfully grown and the compounds adopt the orthorhombic La6MnSb15 structure type (space group Immm), with a~4.3 Å, b~15 Å, and c~19 Å. This structure is comprised of antimony nets and antimony ribbons which exhibit positional disorder at connecting points between antimony substructures, in addition to two partially occupied transition metal sites. The unit cell volumes of the La analogs displayed a systematic decrease upon Zn substitution. However, for the Ce6Mn1−xZnxSb15 and Pr6Mn1−xZnxSb15 (x~0.5), the volumes deviate from linearity as observed in the parent compounds.

Single crystals of LnM x Ga 3 (Ln = Ho, Er; M = Fe, Co; x 3 -structure type where Fe or Co partially occupies the body-centered position of the unit cell surrounded by six Ga atoms. The insertion of Fe or Co guest atoms into the AuCu 3 -structure type causes a structural change in the host material where chemical pressure is exerted on Ga–Ga contacts surrounding the filled octahedra. This in turn affects the stability of the AuCu 3 -structure type and the intrinsic properties of the materials. With increasing Ho–Ho distances of 4.2355(5), 4.2377(5), and 4.2441(3) A, HoCo 0.16(2) Ga 3 , HoFe 0.11(1) Ga 3 , and HoFe 0.16(2) Ga 3 order antiferromagnetically with decreasing Neel temperatures of T N = 10.2, 7.2, and 6.5 K, respectively. ErCo 0.06(2) Ga 3 , ErFe 0.06(1) Ga 3 , and ErFe 0.11(2) Ga 3 order antiferromagnetically with Neel temperatures of T N = 3.3, 5.2, and 6.2 K. The magnetic properties are attributed to changes in the coupling strength of local magnetic moment with conduction electrons as a function of transition metal and rare earth.

Single crystals of Pr2Fe4–xCoxSb5 (1 < x < 2.5) were grown from a Bi flux and characterized by X-ray diffraction. The compounds adopt the La2Fe4Sb5 structure type (I4/mmm). The structure of Pr2Fe4–xCoxSb5 (1 < x < 2.5) contains a network of transition metals forming isosceles triangles. The x ∼ 1 analogue is metallic and exhibits a magnetic transition at T1 ≈ 25 K. The magnetic moment obtained from the Curie–Weiss fit is 11.49(4) μB, which is larger than the spin-only Pr3+ moment. The x ∼ 2 analogue orders magnetically at T1 ≈ 80 and T2 ≈ 45 K. This is the first case of the substitution of Co into the La2Fe4Sb5 structure type, evidenced by the increased concentration of dopant with decreased lattice parameters coupled with a change in the transition temperature with a change in the cobalt concentration. The added complexity in the magnetic behavior of the x ∼ 1 and 2 analogues indicates that the increased concentration of Co invokes an additional magnetic contribution of the transition metal in the sublat...

The discovery of novel magnetic and electronic properties in low-dimensional materials has led to the pursuit of hierarchical materials with specific substructures. Low-dimensional solids are highly anisotropic by nature and show promise in new quantum materials leading to exotic physical properties not realized in three-dimensional materials. We have the opportunity to extend our synthetic strategy of the flux-growth method to designing single crystalline low-dimensional materials in bulk. The goal of this Account is to highlight the synthesis and physical properties of several low-dimensional intermetallic compounds containing specific structural motifs that are linked to desirable magnetic and electrical properties. We turned our efforts toward intermetallic compounds consisting of antimony nets because they are closely linked to properties such as high carrier mobility (the velocity of an electron moving through a material under a magnetic field) and large magnetoresistance (the change in resistivity with an applied magnetic field), both of which are desirable properties for technological applications. The SmSb