Results for “Gd3Ga5O12” | Engineering Papers

DOE OSTI2020

Materials Data on Gd3Ga5O12 by Materials Project

Gd3Ga5O12 crystallizes in the cubic Ia-3d space group. The structure is three-dimensional. Gd3+ is bonded in a distorted body-centered cubic geometry to eight equivalent O2- atoms. There are four shorter (2.38 Å) and four longer (2.52 Å) Gd–O bond lengths. There are two inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to six equivalent O2- atoms to form corner-sharing GaO6 octahedra. All Ga–O bond lengths are 2.03 Å. In the second Ga3+ site, Ga3+ is bonded to four equivalent O2- atoms to form corner-sharing GaO4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. All Ga–O bond lengths are 1.87 Å. O2- is bonded in a 4-coordinate geometry to two equivalent Gd3+ and two Ga3+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Low-temperature nanoscale heat transport in a gadolinium iron garnet heterostructure probed by ultrafast x-ray diffraction

Time-resolved x-ray diffraction has been used to measure the low-temperature thermal transport properties of a Pt/Gd3Fe5O12//Gd3Ga5O12 metal/oxide heterostructure relevant to applications in spin caloritronics. A pulsed femtosecond optical signal produces a rapid temperature rise in the Pt layer, followed by heat transport into the Gd3Fe5O12 (GdIG) thin film and the Gd3Ga5O12 (GGG) substrate. The time dependence of x-ray diffraction from the GdIG layer was tracked using an accelerator-based femtosecond x-ray source. The ultrafast diffraction measurements probed the intensity of the GdIG (1 −1 2) x-ray reflection in a grazing-incidence x-ray diffraction geometry. The comparison of the variation of the diffracted x-ray intensity with a model including heat transport and the temperature dependence of the GdIG lattice parameter allows the thermal conductance of the Pt/GdIG and GdIG//GGG interfaces to be determined. Complementary synchrotron x-ray diffraction studies of the low-temperature thermal expansion properties of the GdIG layer provide a precise calibration of the temperature dependence of the GdIG lattice parameter. The interfacial thermal conductance of the Pt/GdIG and GdIG//GGG interfaces determined from the time-resolved diffraction study is of the same order of magnitude as previous reports for metal/oxide and epitaxial dielectric interfaces. The thermal parameters of the Pt/GdIG//GGG heterostructure will aid in the design and implementation of thermal transport devices and nanostructures.

36 MATERIALS SCIENCE↗