Tuning the melting point and phase stability of rare-earth oxides to facilitate their crystal growth from the meltv  

作　　者：Matheus PIANASSOLA Kaden L.ANDERSON Joshua SAFIN Can AGCA Jake W.MCMURRAY Bryan C.CHAKOUMAKOS Jöerg C.NEUEFEIND Charles L.MELCHER Mariya ZHURAVLEVA 

机构地区：[1]Scintillation Materials Research Center,The University of Tennessee,Knoxville 37996,USA [2]Department of Materials Science and Engineering,The University of Tennessee,Knoxville 37996,USA [3]Materials Science and Technology Division,Oak Ridge National Laboratory,Oak Ridge 37831,USA [4]Neutron Scattering Division,Oak Ridge National Laboratory,Oak Ridge 37831,USA [5]Department of Nuclear Engineering,The University of Tennessee,Knoxville 37996,USA

出　　处：《Journal of Advanced Ceramics》2022年第9期1479-1490,共12页先进陶瓷（英文）

基　　金：This work was supported by the National Science Foundation(DMR 1846935)。

摘　　要：The challenge of growing rare-earth(RE)sesquioxide crystals can be overcome by tailoring their structural stability and melting point via composition engineering.This work contributes to the advancement of the field of crystal growth of high-entropy oxides.A compound with only small REs(Lu,Y,Ho,Yb,Er)_(2)O_(3)maintains a cubic C-type structure upon cooling from the melt,as observed via in-situ high-temperature neutron diffraction on aerodynamically levitated samples.On the other hand,a compound with a mixture of small and large REs(Lu,Y,Ho,Nd,La)_(2)O_(3)crystallizes as a mixture of a primary C-type phase with an unstable secondary phase.Crystals of compositions(Lu,Y,Ho,Nd,La)_(2)O_(3)and(Lu,Y,Gd,Nd,La)_(2)O_(3)were grown by the micro-pulling-down(mPD)method with a single monoclinic B-type phase,while a powder of(Lu,Y,Ho,Yb,Er)_(2)O_(3)did not melt at the maximum operating temperature of an iridium-rhenium crucible.The minimization of the melting point of the two grown crystals is attributed to the mismatch in cation sizes.The electron probe microanalysis reveals that the general element segregation behavior in the crystals depends on the composition.

关 键 词：high-entropy oxides CRYSTALLOGRAPHY neutron diffraction crystal growth 

分 类 号：O7[理学—晶体学]