Structural Study of La<sub>4</sub>MgNi<sub>19</sub> Hydride by In Situ X-ray and Neutron Powder Diffraction

Nakamura, Jin; Iwase, Kenji; Hayakawa, Hiroshi; Nakamura, Yumiko; Akiba, Etsuo

doi:10.1021/jp809890e

Cited by 74 publications

(64 citation statements)

References 35 publications

(53 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5d. The result resembles the tendency [21,22]. However, there is no evident plateau between 0.025 and 0.200 MPa.…”

Section: Microstructuresupporting

confidence: 61%

“…Thus, Location C is determined to be A 5 B 19 -type phase. Two allotropes are reported in A 5 B 19 -type structures, i.e., Pr 5 Co 19 -type (2H) and Ce 5 Co 19 -type (3R) structures [16,21,22]. According to the literatures of Nakamura et al [21] and Zhang et al [22], the specific peak of Ce 5 Co 19 -type structure at 31°-32°does not appear, instead that the peak of Pr 5 Co 19 -type structure at 32°-33°is clearly as shown in Fig.…”

Section: Microstructurementioning

confidence: 99%

See 1 more Smart Citation

Changes of crystal structure and hydrogen storage performances for multiphase La0.7Mg0.3Ni3 alloy upon gas–solid cycling

Zhang

et al. 2014

Rare Met.

View full text Add to dashboard Cite

In order to examine the effects of structure stability on the degradation behaviors of multiphase La 0.7 Mg 0.3 Ni 3 alloy, changes of the crystal structure and hydrogen storage properties after gas-solid cycling were investigated in detail. The structural analysis identifies that (La,Mg)Ni 3 (PuNi 3 -type) phase transforms to amorphous, i.e., hydrogen-induced amorphization(HIA) occurs whereas LaNi 5 (CaCu 5 -type), (La,Mg) 2 Ni 7 (Ce 2 Ni 7 -type), and (La,Mg) 5 Ni 19 (Pr 5 Co 19 -type) phases still keep crystalline upon hydriding/dehydriding cycling. Partial amorphization remarkably affects both the gas-solid and electrochemical storage performances. The plateau of PCT curves becomes narrow and steep with cycling. Moreover, the maximum electrochemical capacity decreases notably after gas-solid hydrogenation repeats. The electrochemical capacity reduction could be ascribed to both drop of the maximum storage capacity and the slope of plateau induced by partial amorphization. For direct electrochemical cycling, it is suggested that the capacity decay is mainly attributed to HIA in the initial stage.

show abstract

“…5d. The result resembles the tendency [21,22]. However, there is no evident plateau between 0.025 and 0.200 MPa.…”

Section: Microstructuresupporting

confidence: 61%

Section: Microstructurementioning

confidence: 99%

Changes of crystal structure and hydrogen storage performances for multiphase La0.7Mg0.3Ni3 alloy upon gas–solid cycling

Zhang

et al. 2014

Rare Met.

View full text Add to dashboard Cite

show abstract

“…The expansion of the [AB 5 -1] layer along the c-axis was larger than that of the [AB 5 -2] layer although the hydrogen content of the [AB 5 -1] layer was around 80% of the [AB 5 -2] layer. The larger expansion of the [AB 5 -1] layer was due to a strain induced by a mismatch between the [AB 5 -1] layer and the [A 2 B 4 ] layer [11]. In the present work, the expansion of the Ce 2 Ni 7 -type phase in La 0.7 Mg 0.3 Ni 2.8 Co 0.5 by hydrogen absorption was isotropic.…”

Section: Resultssupporting

confidence: 43%

“…Nakamura et al [11] have reported that the crystal structure of the hydride of the Pr 5 Co 19 -type phase in La 4 MgNi 19 was determined using the X-ray and neutron diffraction measurements. The Pr 5 Co 19 -type phase shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Phase transformation of the La0.7Mg0.3Ni2.8Co0.5-H2 system studied by in situ X-ray diffraction

Chai

Asano

Sakaki

et al. 2009

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

A Novel Synthesis Method of La–Mg‐Ni‐based Superlattice by LaNi₅ Absorbing Gas‐state Mg

Zhao

Cai

et al. 2019

ChemistrySelect

View full text Add to dashboard Cite

La−Mg‐Ni based alloys are considered as future negative material for Ni‐MH batteries, while the volatilization of Mg hinders their application. Mg volatilization is considered irreversible in the preparation process. Herein, we provide a novel process to produce superlattice La−Mg‐Ni‐based alloy via alloying gas‐state Mg with LaNi5 slice. The formation of superlattice structures is verified in detail by microstructure characterization and element distribution analysis. The results indicate that there exists an equilibrium state for Mg solution in the La−Mg‐Ni alloy, and the gas‐state Mg atoms are directly absorbed by the LaNi5 alloy. With increasing the absorption time, Mg in LaNi5 slice bends to become more homogenous. It is attributed that the integration of the gas‐state Mg atoms leads to the transformation of the crystal structure of the LaNi5 cells on the slice surface into MgCu4Sn‐type phase, thus the solid LaNi5 phase turn to liquid MgCu4Sn‐type phase under the high temperature. Further, the liquid phase permeates into the inside of the LaNi5 slice along crystal boundaries which alloys with LaNi5 lattices to form Ce2Ni7‐type phase. This technology proves that the migration of metal atoms in gas state can induce a regroup phenomenon to form solid state crystal and provides a brand method for hydrogen storage materials preparation.

show abstract

Structural Study of La₄MgNi₁₉ Hydride by In Situ X-ray and Neutron Powder Diffraction

Abstract: In situ X-ray and neutron powder diffraction were carried out for the La 4 MgNi 19 alloy sample, which was obtained by annealing under controlled Mg-vapor pressure and temperature. The sample contained five phases:

Cited by 74 publications

References 35 publications

Changes of crystal structure and hydrogen storage performances for multiphase La0.7Mg0.3Ni3 alloy upon gas–solid cycling

Changes of crystal structure and hydrogen storage performances for multiphase La0.7Mg0.3Ni3 alloy upon gas–solid cycling

Phase transformation of the La0.7Mg0.3Ni2.8Co0.5-H2 system studied by in situ X-ray diffraction

A Novel Synthesis Method of La–Mg‐Ni‐based Superlattice by LaNi₅ Absorbing Gas‐state Mg

Contact Info

Product

Resources

About

Structural Study of La4MgNi19 Hydride by In Situ X-ray and Neutron Powder Diffraction

Abstract: In situ X-ray and neutron powder diffraction were carried out for the La 4 MgNi 19 alloy sample, which was obtained by annealing under controlled Mg-vapor pressure and temperature. The sample contained five phases:

Cited by 74 publications

References 35 publications

Changes of crystal structure and hydrogen storage performances for multiphase La0.7Mg0.3Ni3 alloy upon gas–solid cycling

Changes of crystal structure and hydrogen storage performances for multiphase La0.7Mg0.3Ni3 alloy upon gas–solid cycling

Phase transformation of the La0.7Mg0.3Ni2.8Co0.5-H2 system studied by in situ X-ray diffraction

A Novel Synthesis Method of La–Mg‐Ni‐based Superlattice by LaNi5 Absorbing Gas‐state Mg

Contact Info

Product

Resources

About

Structural Study of La₄MgNi₁₉ Hydride by In Situ X-ray and Neutron Powder Diffraction

A Novel Synthesis Method of La–Mg‐Ni‐based Superlattice by LaNi₅ Absorbing Gas‐state Mg