Lithium fluoride: from LiF:Mg,Ti to LiF:Mg,Cu,P

Area of Science:

• Materials Science
• Solid State Physics
• Radiation Dosimetry

Background:

• Lithium fluoride (LiF) based phosphors are widely used in radiation dosimetry.
• Understanding dopant roles (Mg, Ti, Cu, P) is crucial for optimizing dosimetric properties like sensitivity and dose response linearity.
• New hybrid phosphors LiF:Mg,Cu,Ti and LiF:Mg,P were developed to further investigate dopant effects.

Purpose of the Study:

• To compare dosimetric properties of LiF:Mg,Ti and LiF:Mg,Cu,P phosphors.
• To elucidate the individual and combined roles of Mg, Ti, Cu, and P dopants.
• To investigate the properties of novel LiF:Mg,Cu,Ti and LiF:Mg,P phosphors.

Main Methods:

• Analysis of dosimetric properties: sensitivity, non-linearity of dose response, and heavy charged particle efficiency.
• Characterization of glow curves and emission spectra of various LiF phosphors.
• Correlation of dopant concentrations with observed dosimetric behaviors.

Main Results:

• Magnesium concentration is a primary factor controlling dosimetric properties, including sensitivity and dose response.
• Charged-particle efficiency shows an inverse correlation with magnesium concentration.
• A new glow curve peak in LiF:Mg,Cu,P (low Mg) was observed, analogous to peak 4 in LiF:Mg,Ti.
• Titanium appears to limit magnesium incorporation into traps in LiF:Mg,Ti.

Conclusions:

• Magnesium plays a dominant role in the dosimetric characteristics of LiF-based phosphors.
• The high sensitivity of LiF:MgCuP is attributed to the absence of titanium, rather than the presence of copper or phosphorus.
• Dopant interactions and their effect on trap dynamics influence phosphor performance.