Related Experiment Video
Updated: Jul 12, 2026
08:44
Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene
Published on: August 22, 2017
X-ray diffaction evidence for nonstoichiometric rubidium-c60 intercalation compounds
Science (New York, N.Y.)
|October 25, 1991
Summary
This study reveals new phases in Rubidium fulleride (Rb(chi)C(60)) using powder X-ray diffraction. New doped and substoichiometric phases were identified, expanding understanding of Rb(chi)C(60) materials.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Crystallography
Background:
- Rubidium fullerides (Rb(chi)C(60)) are known for their superconducting properties.
- Understanding the phase behavior of Rb(chi)C(60) is crucial for optimizing its electronic properties.
Purpose of the Study:
- To investigate the phase diagram of Rubidium fulleride (Rb(chi)C(60)) at 300 K.
- To identify and characterize new stoichiometric and non-stoichiometric phases.
Main Methods:
- Powder X-ray diffraction (XRD) was employed to analyze equilibrated samples.
- Samples with varying nominal compositions (chi) of Rb(chi)C(60) were studied.
Main Results:
- The study identified face-centered cubic (fcc), body-centered tetragonal (bct), and body-centered cubic (bcc) stoichiometric phases.
- Direct evidence for a dilute fcc doped phase (0 <= chi <= 1) and a substoichiometric bcc phase (chi approx 5) was found.
- The chi = 3 (superconducting) and chi = 4 phases appear to be line phases with limited solubility.
Conclusions:
- A provisional binary phase diagram for Rb(chi)C(60) was established.
- The findings provide a more comprehensive understanding of the structural and compositional landscape of Rubidium fullerides.
Related Concept Videos
02:18X-ray Crystallography
The size of the unit cell and the arrangement of atoms in a crystal may be determined from measurements of the diffraction of X-rays by the crystal, termed X-ray crystallography.
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
01:29Determination of Crystal Structures
In the late 1800s, the revelation that light extended beyond visible wavelengths led to the discovery of X-rays by Wilhelm Roentgen. Recognized as high-energy electromagnetic radiation with short wavelengths, X-rays prompted exploration into their interaction with crystals. Max von Laue proposed in 1912 that the periodic arrangement of atoms, ions, or molecules in crystals would cause them to diffract X-rays, a hypothesis confirmed through experiments with copper sulfate and zinc sulfide...
01:10X-ray Diffraction of Biological Samples
X-ray diffraction or XRD is an analytical tool that utilizes X-rays to study ordered structures such as crystalline organic and inorganic samples, polycrystalline materials, proteins, carbohydrates, and drugs.
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
01:26Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
01:29Imperfections in Crystal Structure: Non-Stoichiometric Defects
Non-stoichiometric defects refer to a type of defect in the crystal structure of a compound where the ratio of its constituent elements deviates from the ideal stoichiometric ratio. There are two main types of non-stoichiometric defects: metal excess defects and metal deficiency defects.Metal excess defects occur when there is a slight surplus of metal ions than what is required by the stoichiometric ratio of the compound. For example, heating a sodium chloride crystal in sodium vapor results...
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...