Related Experiment Video
Updated: Jun 22, 2026
04:14
Facile Synthesis of Colloidal Lead Halide Perovskite Nanoplatelets via Ligand-Assisted Reprecipitation
Published on: October 1, 2019
Building alkali-metal-halide layers within a perovskite host by sequential intercalation: (A(2)Cl)LaNb(2)O(7) (A =
Jonglak Choi1, Xiao Zhang, John B Wiley
1Department of Chemistry and the Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148, USA.
Inorganic Chemistry
|May 27, 2009
Summary
Researchers created novel Dion-Jacobson layered perovskites by inserting alkali-metal-halide layers. This new synthesis method yields unique layered structures with potential applications in materials science.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Inorganic Chemistry
Background:
- Dion-Jacobson (DJ) layered perovskites are a class of materials with tunable properties.
- Intercalation methods offer pathways to modify layered structures.
- Introducing halide layers into perovskites can alter their electronic and structural characteristics.
Purpose of the Study:
- To synthesize novel layered perovskite compounds incorporating alkali-metal-halide layers.
- To investigate the structural and chemical properties of these new materials.
- To establish a general method for creating such intercalated structures.
Main Methods:
- A two-step sequential intercalation method was employed.
- Reductive intercalation with alkali metals followed by oxidative intercalation with chlorine gas.
- Rietveld refinement of X-ray powder diffraction data for structural analysis.
- Thermal analysis (TGA/DSC) to determine thermal stability.
Main Results:
- Successfully synthesized new compounds (A(2)Cl)LaNb(2)O(7) where A = Rb, Cs.
- Confirmed the formation of an alkali-metal-halide layer between perovskite blocks.
- Characterized the eight-coordinate environment of alkali-metal cations within the halide layer.
- Identified these phases as low-temperature materials, decomposing above 400°C.
Conclusions:
- The two-step sequential intercalation method is effective for constructing alkali-metal-halide layers within DJ perovskites.
- The synthesized compounds exhibit unique structural features with potential for further research.
- This approach provides a versatile route for designing novel layered inorganic materials.
Related Concept Videos
02:37Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
02:48Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
02:46Halogenation of Alkenes
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
03:06Alkali Metals
Group 1 elements are soft and shiny metallic solids. They are malleable, ductile, and good conductors of heat and electricity. The melting points of the alkali metals are unusually low for metals and decrease going down the group, while the density increases going down the group with the exception of potassium (Table 1).
Table 1: Properties of the alkali metals
Table 1: Properties of the alkali metals