Rare-earth chromium gallides RE4CrGa12 (RE=Tb–Tm)

Filling in the Holes: Structural and Magnetic Properties of the Chemical Pressure Stabilized LnMnxGa3 (Ln = Ho–Tm; x < 0.15)

“…Indeed, cubic LnGa 3 (Ln = Er, Tm) phases adopting the AuCu 3 structure type are known to exhibit unique magnetic properties resulting from CEF effects 25 CrGa 12 that guest atom incorporation can lead to favorable Ga−guest bonding. 8 Another clue to the forces at work here can be seen in the crystal structures of the LnMn x Ga 3 phases described above and the previously reported Y 4 PdGa 12 -type superstructures: inclusion of a stuffing atom involves substantial displacement of the surrounding Ga atoms (Figure 1b and 1c), reflecting the need for a local expansion of the structure to accommodate the atomic size of the guest atom.…”

“…Ln 4 FeGa 12 (Ln = Y, Tb−Er) adopt the ordered Y 4 PdGa 12 structure type except for the Er member, Er 4 Fe 0.67 Ga 12 , which exhibits Ga site splitting and two Fe sites that are partially occupied. 8 For Y 4 Mn x Ga 12−y Ge y (x = 0.74−1.00, y = 0−4.0), Mn occupancy varies as a function of Ge concentration (y). 9 At y = 4.0, the Mn site is near full occupancy (x = 0.95), and the phase is paramagnetic.…”

“…Despite being one of the simplest inorganic crystal structures, the four-atom unit cell of the AuCu 3 type underlies remarkable physical properties. This is illustrated by CeIn 3, which exhibits magnetically mediated superconductivity at the critical temperature ( T c ) ≈ 0.2 K at 27 kbar. , Furthermore, the AuCu 3 type is able to accommodate transition metal (M) atoms in its octahedral holes which could be used to the tune properties of these compounds. − …”

Putting ScTGa5(T = Fe, Co, Ni) on the Map: How Electron Counts and Chemical Pressure Shape the Stability Range of the HoCoGa5Type

“…Clues to how atomic sizes may influence the favorability of the HoCoGa 5 type can be found in our earlier CP analysis of the Y 4 PdGa 12 structure type, which can accommodate larger transition metal atoms into the octahedral holes of a AuCu 3 -like YGa 3 network (Figure a). − A hypothetical “YGa 3 ” phase was found to be destabilized by the stretching of the Ga–Ga interactions due to the relatively large size of the Y atoms. Filling 1/4 of the octahedral holes with a transition metal atom was found to relieve this situation in two ways: (1) the presence on the T atoms replaced the overly long the Ga–Ga contacts in their Ga 6 environment with nearly ideal T–Ga ones, and (2) the expansion of the stuffed Ga 6 octahedron compresses the Ga–Ga distances in neighboring unstuffed octahedra.…”

U8Al19Si6, A Uranium Aluminide Silicide with a Stuffed Supercell Grown from Aluminum Flux

“…In the structure of U 8 Al 19 Si 6 , 1/8 of these octahedral sites are filled (shown in Figure d). Several other intermetallic structures can be viewed as “stuffed” Cu 3 Au structure types; these include TmMn x Ga 3 , Y 4 CrGa 12 , and Y 4 Mn 1– x (Ga/Ge) 12 . − The different stuffing patterns of the extra atoms in these structures leads to different unit cell sizes, symmetries, and overall stoichiometries. U 8 Al 19 Si 6 exhibits a new stuffing pattern and accordingly a new supercell.…”