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Properties and Applications of Rare Earth Oxides, Alloys, and Compounds
Published in A. R. Jha, Deployment of Rare Earth Materials in Microware Devices, RF Transmitters, and Laser Systems, 2019
Research studies undertaken by the oxides reveal that certain rare earth oxides are best suited for specific commercial, military, and medical applications. Comprehensive research studies undertaken by the author on specific rare earth oxides indicate that thulium oxide and holmium oxide are best suited for infrared lasers. Radiation studies seem to indicate that gre ater radiation danger can be expected from the processed REEs than from the processed oxides. Mild radiation danger can be expected from rare earth isotopes, if they are not handled with extreme care. It should be mentioned that the radiation danger is strictly dependent on the half-life of the isotope. Doctors, nurses, and lab technicians must be familiar with the half-life of the rare earth isotopes, if they are using rare earth isotopes in medical treatment. This is absolutely essential to avoid irreversible health injury to the patient.
Erbium-Doped Fibre Lasers
Published in Shyamal Bhadra, Ajoy Ghatak, Guided Wave Optics and Photonic Devices, 2017
Aditi Ghosh, Deepa Venkitesh, R. Vijaya
In long-haul fibre communication, the use of wavelength-division multiplexed systems has increased the information-carrying capacity of the existing optical networks to a significant extent. In this technology, data are modulated at different wavelengths and are simultaneously propagated. To cater to the demand for an increasing number of channels in communication systems, high signal powers, greater than 20 dBm, are required at the output of each amplifier in the network link. The discovery of all-optical amplifiers based on the lasing principles in rare-earth-doped fibres, first reported by the University of Southampton in 1987 [12], provided a major technological breakthrough in the practical realization of long-haul communication networks. While doping the fibre with erbium ions results in amplification in the wavelength range of 1550 nm, ytterbium doping leads to amplification in the 1064 nm region. Thulium- and holmium-doped fibres are widely used to provide amplification in the mid-infrared region. A detailed description of the spectroscopic properties of these doped fibres can be found in Digonnet [13].
Solution Purification
Published in C. K. Gupta, T. K. Mukherjee, Hydrometallurgy in Extraction Processes, 2017
Lever and Payne75 attempted a similar technique while using Zeokarb 225 cation exchange resin, but were confronted with the problem of the formation of crystals of Cu-EDTA compound which eventually blocked the column. The investigators finally made use of the “self-retaining” effect of the rare earths among themselves where heavier earths acted as retaining ions to their lighter neighbors. Elution of a 100-mm diameter x 9-m long column loaded with 8 kg of rare earths from xenotime resulted in a first fraction containing 80% of ytterbium and lutetium. These were followed by concentrates of thulium, erbium, holmium, dysprosium, and finally, 98% pure yttrium.
Biospecific separation of holmium(III) using raw and chemically treated bark powder of Mangifera indica: kinetics, isotherm and thermodynamic studies
Published in Environmental Technology, 2021
Pravat Manjari Mishra, Loparani Barick, Aparna Prabha Devi, Krishna Kumari Swain
Rare earth metals (REMs) are becoming increasingly important because of their applications in the field of chemical engineering, metallurgy, nuclear energy, optical, magnetic, luminescence and laser materials, high-temperature superconductors and secondary batteries, etc. [1–3]. Out of which, Holmium(III) is regarded as an important REM because of its wide utilization in ceramics, lasers, nuclear industry, treatment of glaucoma, etc. Different methods have been proposed for separation and preconcentration of Holmium, such as co-precipitation, solvent extraction, ion-exchange and solid-phase extraction [4,5]. These traditional methods have some disadvantages such as high consumption of reagent and energy, low selectivity, high operational cost and generation of secondary toxic metabolites that are hazardous to the environment. Therefore, there is a need to develop a cost-effective as well as an eco-friendly method to recover REMs in a large scale.