Related Experiment Video
Updated: Dec 25, 2025
09:06
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.5K
Temperature induced valence phase transition in intermediate-valent YbPd2Al3
Frank Stegemann1, Juliane Stahl2, Manfred Bartsch3
1Institut für Anorganische und Analytische Chemie , Westfälische Wilhelms-Universität Münster , Corrensstraße 30 , D-48149 Münster , Germany .
Chemical Science
|March 25, 2020
Summary
A temperature-induced valence phase transition was observed in YbPd2Al3, shifting from Yb3+ to Yb2+ at 110 K. This transition impacts the material's electronic structure and crystal lattice.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Solid State Chemistry
Background:
- Intermetallic compounds containing Ytterbium (Yb) often exhibit interesting electronic and magnetic properties due to the Yb ion's valence states.
- Understanding valence transitions is crucial for designing materials with tunable electronic behaviors.
Purpose of the Study:
- To investigate the temperature-induced valence phase transition in intermetallic YbPd2Al3.
- To characterize the structural, magnetic, and electronic properties associated with this transition.
Main Methods:
- Single-crystal and powder X-ray diffraction for structural analysis.
- Magnetic susceptibility (dc and ac) and heat capacity measurements to probe magnetic and thermodynamic properties.
- Electrical resistivity measurements to study electronic transport.
- X-ray photoelectron spectroscopy (XPS) to determine Yb valence states.
Main Results:
- A hexagonal YNi2Al3 type structure (space group P6/mmm) was confirmed for YbPd2Al3 with lattice parameters a = 929.56(7) pm and c = 420.16(3) pm at 300 K.
- A valence phase transition from Yb3+ to Yb2+ was observed around 110 K, evidenced by magnetic susceptibility, heat capacity (lambda-type anomaly), and a steep increase in the c-axis length upon cooling.
- XPS confirmed the mixed-valent state of Yb, showing the presence of both Yb2+ and Yb3+ ions.
- No antiferromagnetic ordering or spin-glass behavior was detected.
- Solid solutions of Yb1-xCaxPd2Al3 were synthesized to further study charge ordering and the valence transition.
Conclusions:
- YbPd2Al3 undergoes a significant temperature-induced valence phase transition at approximately 110 K.
- This transition is accompanied by changes in crystal structure (c-axis length) and electronic properties, without magnetic ordering.
- The study provides insights into the complex interplay of valence, structure, and electronic behavior in Yb-based intermetallic compounds.
Related Concept Videos
02:31Phase Transitions
22.2K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
22.2K
02:33Phase Transitions: Sublimation and Deposition
19.4K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
19.4K
02:39Phase Transitions: Vaporization and Condensation
20.4K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
20.4K
02:39Phase Transitions: Melting and Freezing
14.4K
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
14.4K
02:42Valence Bond Theory
10.9K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
10.9K
01:19Phase Diagram
6.8K
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
6.8K