Superconductivity Study On LK-99 Material

GS Paper III Science and Technology

Context:

Researchers from China and Japan have identified indications of superconductivity in the contentious material LK-99.

The researchers identified a near-RTP superconductivity indication LK-99.
The researchers witnessed the manifestation of the Meissner effect in LK-99.
The new group used an advanced synthesis method for LK-99 samples and conducted additional tests for different superconductivity indicators.
They performed hysteresis experiments by applying and removing a magnetic field to observe how the material responds at different temperatures, utilizing direct current measurements.

When a material shifts from a normal to a superconducting state, it actively repels magnetic fields from its interior.
- This phenomenon is known as the Meissner effect.

Direct current (DC) measurements involve altering the material’s physical conditions to induce a transition to a superconducting state.

Definition: It is as a superconductor under the conditions of room temperature and standard atmospheric pressure.
LK-99 comprises powdered lead, oxygen, sulfur, and phosphorus compounds.
Subjected to high temperatures, it transforms into a dark grey solid.
Korean scientists have suggested its potential as a room temperature and pressure (RTP) superconductor.

LK-99

Apatite Structure: Created using copper-substituted lead apatite, a phosphate mineral with unique tetrahedral motifs.
Superconducting Behavior: LK-99 displayed essential superconducting traits, including minimal resistance to current flow and the emergence of resistance beyond a critical current threshold.
Magnetic Resilience: Maintained superconductivity in a magnetic field until reaching a critical threshold.

It is the property of certain materials to conduct direct current (DC) electricity without energy loss when they are cooled below a critical temperature (referred to as Tc).
These materials also expel magnetic fields as they transition to the superconducting state.

LK-99

Superconductors are substances that, when cooled to extremely low temperatures, display a complete absence of electrical resistance.
It enables the transmission of electricity without any energy loss.
Note: Two common low-temperature superconductors: lead and mercury.

Two types of superconductors, determined in part by their response to a magnetic field.

Type I superconductors lose their superconducting state entirely when exposed to a strong magnetic field, allowing field penetration into the material.
Type II superconductors gradually reduce superconductivity as the magnetic field strength increases, completely vanishing at a higher threshold.

The study faced limitations due to the small size of the superconducting portions in the material, resulting in a reduced critical magnetic field strength.
Molecular structure analysis using X-rays was impeded by the interference caused by cuprous sulphide.

News source: The Hindu