Radu-Cristian Gavrea

Dr. Radu-Cristian Gavrea

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Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 May 2024 in Crystals
Verified
Journal Article
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Mioara ZagraiMioara Zagrai
Mioara Zagrai
RGRadu-Cristian Gavrea
Radu-Cristian Gavrea
GMGabriel Sergiu Gabriel MACAVEI
Gabriel Sergiu Gabriel MACAVEI
ADAdriana Dehelean
Adriana Dehelean
APAdriana Popa
Adriana Popa
RALUCA ANCA MEREURALUCA ANCA MEREU
RALUCA ANCA MEREU
The present study aimed to test the solubility of SiO2 in a PbO2 host glass matrix. The new glass system with chemical composition xSiO2∙(100-x)∙PbO2 (in mol%) was obtained at low temperature using the melt-quenching technique. The method proposed for the characterization of the glass system includes X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), inductively coupled plasma mass spectrometry (ICP-Ms), Fourier Transform Infrared (FTIR), and Electron Spin Resonance (ESR) spectroscopy. Understanding the relationship between the oxide composition, structure, chemical durability, and thermal characteristics of obtained materials is essential for further developing the new glass crystalline material (GCM) compositions with specific desired properties.

16 January 2025 in Applied Sciences
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Journal Article
Open access
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Mioara ZagraiMioara Zagrai
Mioara Zagrai
Suciu Ramona CrinaSuciu Ramona Crina
Suciu Ramona Crina
RGRadu-Cristian Gavrea
Radu-Cristian Gavrea
VRVasile Rednic
Vasile Rednic
This study explores the physical, radiation shielding, optical, and photoluminescent properties of PbO2-SiO2-based glass systems. Traditional radiation shielding materials, like lead and concrete, face challenges due to toxicity and weight. Glass materials provide an alternative, offering transparency and efficiency. Four glass systems were analyzed: PbO2-SiO2 (PS), PbO2-SiO2-CeO2 (PSC), PbO2-SiO2-Eu2O3 (PSE), and PbO2-SiO2-Yb2O3 (PSY). The results show that rare earth elements densify the glass network, thereby enhancing radiation attenuation properties, quantified through parameters like the linear attenuation coefficient (μ), the half-value layer (HVL), and the mean free path (MFP). The PSY system exhibited the best shielding properties, demonstrating its potential for use in gamma ray shielding. Samples PS0–PS3 revealed semiconducting behavior and may be considered a promising host matrix for solar cells and w-LED applications.

19 June 2025 in Crystals
Verified
Journal Article
Open access
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RGRadu-Cristian Gavrea
Radu-Cristian Gavrea
ESEmanoil Surducan
Emanoil Surducan
HRHirian Razvan
Hirian Razvan
Mioara ZagraiMioara Zagrai
Mioara Zagrai
VRVasile Rednic
Vasile Rednic
Lead–bismuth eutectic alloy (LBE, Pb44.5Bi55.5) has emerged as a promising candidate for use in advanced nuclear and solar energy systems due to its favorable thermophysical characteristics and radiation shielding capabilities. The aim of this research is to assess the applicability of the induction melting technique to synthesize LBE. This paper presents a comprehensive evaluation of the structural, thermophysical, and radiation shielding properties of the obtained LBE sample. Various techniques were employed to investigate the solid-to-liquid eutectic transformation, phase composition, morphology, and homogeneity of the obtained material. Experimental and theoretical determinations on density, void, molar volume, thermal conductivity, heat capacity, thermal diffusivity, and electrical conductivity were performed. Radiation shielding performance over photon energies ranging from 0.015 to 15 MeV was simulated using the Phy-X/PSD program. The results revealed the eutectic structure comprising Pb7Bi3 and Bi phases with near-ideal stoichiometry and a melting point of 127.6 °C. The alloy demonstrated a small void that corresponds to a high degree of sample compaction, high specific heat capacity, moderate thermal conductivity, low thermal diffusivity, and effective radiation shielding. These findings confirm that LBE obtained by the induction melting technique possesses the necessary structural stability and functional properties for integration into nuclear reactor and solar thermal technologies.