It was revealed that an average energy of special boundaries is proportional to APB energy in the alloys with the L12 superstructure. This fact proves the appearance of the GAPBs in the planes of location of special b...It was revealed that an average energy of special boundaries is proportional to APB energy in the alloys with the L12 superstructure. This fact proves the appearance of the GAPBs in the planes of location of special boundaries in coincidence sites of ordered alloys. It was determined that the more energy of special boundaries in ordered alloys, the more energy of complex stacking fault. There is a correlation between the distribution of special boundaries as a function its relative energy and ordering energy: the more ordering energy, the more degree of washed away of distribution. The correlation between average relative energy of special boundaries and ordering energy was detected: the more ordering energy, the more average energy of special boundaries. The reverse dependence between ordering energy and average number of special boundaries in grains limited by boundaries of general type was discovered.展开更多
Superlattices in crystals,particularly in perovskite oxides with strong correlation effects,can create new states of matter and produce peculiar physicochemical phenomena.However,the newfangled perovskite superlattice...Superlattices in crystals,particularly in perovskite oxides with strong correlation effects,can create new states of matter and produce peculiar physicochemical phenomena.However,the newfangled perovskite superlattices depend on physical deposition with unit-cell precision.It has been challenging to explore a new suitable chemical method to tailor perovskite superlattices.Herein,we present a new bottomup strategy to precisely prepare atomic-scale oxide superlattices of(LaMnO_(3))_(1)-(La_(1-x-y)Ca_(x)K_(y)MnO_(3))_(2)in a monodispersed perovskite La_(0.66)Ca_(0.29)K_(0.05)MnO_(3)(LCKMO).The special atomic-scale perovskite superlattices are demonstrated using SAED,HAADF-STEM,XRD,and atomic-resolution elemental mapping.Our experiments reveal that the perovskite superlattices can be fabricated under extreme hydrothermal conditions utilizing ultra-high concentrations of KOH.An approximate molten salt system in the hydrothermal process can induce the disproportionation reaction of MnO_(2)solids,which is vital to the growth of ordered perovskite superlattices.This work not only clarifies the hydrothermal growth process of perovskite oxides in extreme conditions,but also proposes a novel engineering route toward perovskite superlattices.展开更多
基金B.V.Konovalova., N.A. Koneva and E.V.Kozlov acknowledge the INTAS for the partial support of this research under INTAS97-319
文摘It was revealed that an average energy of special boundaries is proportional to APB energy in the alloys with the L12 superstructure. This fact proves the appearance of the GAPBs in the planes of location of special boundaries in coincidence sites of ordered alloys. It was determined that the more energy of special boundaries in ordered alloys, the more energy of complex stacking fault. There is a correlation between the distribution of special boundaries as a function its relative energy and ordering energy: the more ordering energy, the more degree of washed away of distribution. The correlation between average relative energy of special boundaries and ordering energy was detected: the more ordering energy, the more average energy of special boundaries. The reverse dependence between ordering energy and average number of special boundaries in grains limited by boundaries of general type was discovered.
基金supported by National Natural Science Foundation of China(Nos.21831003,21801090 and 22293041)China Postdoctoral Science Foundation(No.2019M661203)Users with Excellence Program of Hefei Science Center CAS(No.2020HSC-UE002).
文摘Superlattices in crystals,particularly in perovskite oxides with strong correlation effects,can create new states of matter and produce peculiar physicochemical phenomena.However,the newfangled perovskite superlattices depend on physical deposition with unit-cell precision.It has been challenging to explore a new suitable chemical method to tailor perovskite superlattices.Herein,we present a new bottomup strategy to precisely prepare atomic-scale oxide superlattices of(LaMnO_(3))_(1)-(La_(1-x-y)Ca_(x)K_(y)MnO_(3))_(2)in a monodispersed perovskite La_(0.66)Ca_(0.29)K_(0.05)MnO_(3)(LCKMO).The special atomic-scale perovskite superlattices are demonstrated using SAED,HAADF-STEM,XRD,and atomic-resolution elemental mapping.Our experiments reveal that the perovskite superlattices can be fabricated under extreme hydrothermal conditions utilizing ultra-high concentrations of KOH.An approximate molten salt system in the hydrothermal process can induce the disproportionation reaction of MnO_(2)solids,which is vital to the growth of ordered perovskite superlattices.This work not only clarifies the hydrothermal growth process of perovskite oxides in extreme conditions,but also proposes a novel engineering route toward perovskite superlattices.