Results for “LaMnSi” | Engineering Papers

DOE OSTI2020

Materials Data on LaMnSi by Materials Project

LaMnSi is Matlockite structured and crystallizes in the tetragonal P4/nmm space group. The structure is two-dimensional and consists of one LaMnSi sheet oriented in the (0, 0, 1) direction. La2+ is bonded in a 4-coordinate geometry to four equivalent Si4- atoms. All La–Si bond lengths are 3.06 Å. Mn2+ is bonded to four equivalent Si4- atoms to form a mixture of edge and corner-sharing MnSi4 tetrahedra. All Mn–Si bond lengths are 2.42 Å. Si4- is bonded in a 8-coordinate geometry to four equivalent La2+ and four equivalent Mn2+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2024

Unconventional pressure-induced magnetic transitions and mechanical properties in non-magnetic LaFeSi

Here, this work demonstrates that two consecutive magnetic transitions occur in non-magnetic LaFeSi compound under negative hydrostatic pressure (small volume expansion). Electronic structure properties of LaFeSi were calculated using density functional theory (DFT) to understand the origin of these magnetic transitions. Mechanical properties of LaFeSi, especially elastic properties (shear and Young’s modulus, and Poisson’s ratio), were determined by DFT distortion calculations to elucidate lattice anisotropy and stability. The antiferromagnetic transition at –7.52 GPa, predicted in our work for LaFeSi, is consistent with the reported experimentally observed antiferromagnetic ground states in CeMnSi and LaMnSi compounds having similar crystal geometry. This finding of unexpected magnetic ordering predicts that layered non-magnetic materials, like LaFeSi, may become magnetically active with lattice expansion.

36 MATERIALS SCIENCE↗