Coupled magnetic excitations in single crystal PrBa(2)Cu(3)O(6.2)

Area of Science:

• Condensed matter physics
• Materials science
• Magnetism

Background:

• Understanding magnetic excitations is crucial for characterizing complex magnetic materials.
• Praseodymium-based cuprates exhibit unique magnetic properties due to competing interactions.
• The ordering temperature of the Pr sublattice in PrBa(2)Cu(3)O(6.2) is anomalously high.

Purpose of the Study:

• To determine the dispersion of low-energy magnetic excitations of the Pr sublattice.
• To investigate the interactions between the Pr and Cu magnetic sublattices.
• To quantify exchange constants and understand the factors contributing to the high Pr ordering temperature.

Main Methods:

• Inelastic neutron scattering measurements on a single crystal of PrBa(2)Cu(3)O(6.2).
• Analysis using a model of the coupled Cu-Pr magnetic system.
• Measurement of the Cu optic spin wave mode.

Main Results:

• The magnetic excitation dispersion of the Pr sublattice was determined.
• The dispersion is well-described by a coupled Cu-Pr magnetic system model.
• Both Pr-Pr and Cu-Pr interactions were found to be significant for the high Pr ordering temperature.
• Interlayer Cu-Cu exchange was found to be significantly lower than in YBa(2)Cu(3)O(6.2).

Conclusions:

• The study successfully characterized the magnetic excitations and interactions in PrBa(2)Cu(3)O(6.2).
• Pr-Pr and Cu-Pr interactions are key to the high ordering temperature of the Pr sublattice.
• Reduced interlayer Cu-Cu exchange is a notable feature of this material compared to YBa(2)Cu(3)O(6.2).