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Mechanical alloying of Mg-Zn-Ca-Er alloy

Hrapkowicz Bartłomiej, Lesz Sabina, Kremzer Marek, Karolus Małgorzata, Pakieła Wojciech

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 5

art. no. e137587

EN

Magnesium-based materials constitute promising alternatives for medical applications, due to their characteristics, such as good mechanical and biological properties. This opens many possibilities for biodegradable materials to be used as less-invasive options for treatment. Degradation is prompted by their chemical composition and microstructure. Both those aspects can be finely adjusted by means of proper manufacturing processes, such as mechanical alloying (MA). Furthermore, MA allows for alloying elements that would normally be really hard to mix due to their very different properties. Magnesium usually needs various alloying elements, which can further increase its characteristics. Alloying magnesium with rare earth elements is considered to greatly improve the aforementioned properties. Due to that fact, erbium was used as one of the alloying elements, alongside zinc and calcium, to obtain an Mg₆₄Zn₃₀Ca₄Er₁ alloy via mechanical alloying. The alloy was milled in the SPEX 8000 Dual Mixer/Mill high energy mill under an argon atmosphere for 8, 13, and 20 hours. It was assessed using X-ray diffraction, energy dispersive spectroscopy and granulometric analysis as well as by studying its hardness. The hardness values reached 232, 250, and 302 HV, respectively, which is closely related to their particle size. Average particle sizes were 15, 16, and 17 μm, respectively.

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Magnetic characterization of microcrystalline Na3Ln0.99–xEr0.01Crx(PO4)2 orthophosphates synthesized by Pechini method (Ln = La, Gd)

Kaczmarek S. M., Leniec G., Fuks H., Skibiński T., Pelczarska A., Godlewska P., Hanuza J., Szczygieł I.

Materials Science Poland

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2017

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Vol. 35, No. 4

733--745

EN

Na3Ln(PO4)2 orthophosphates (Ln = La, Gd) doped with Er3+ and co-doped with Cr3+ ions were synthesized by Pechini method and characterized by electron paramagnetic resonance (EPR) and magnetic susceptibility measurements. Low temperature EPR spectra were detected and analyzed in terms of temperature dependence and the structure of the obtained materials. They show that erbium and chromium ions substitute Ln3+ and also Na+ ions or Na+ channels forming complex EPR spectra. Both kinds of ions reveal ferromagnetic type of interaction which shows some anomaly at the temperature between 10 K and 15 K. Magnetic susceptibility reveals a weak antiferromagnetic kind of interaction dominating in the whole temperature range, from 3.5 to 300 K.

3

Growth and EPR properties of ErVO4 single crystals

Leniec G., Kaczmarek S. M., Berkowski M., Głowacki M., Skibiński T., Bojanowski B

Nukleonika

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2015

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Vol. 60, No. 3, part 1

405--410

EN

Single crystals of ErVO4 were grown by the Czochralski method under ambient pressure in a nitrogen atmosphere. Obtained crystals were transparent with strong pink coloring. Electron paramagnetic resonance (EPR) spectra were recorded as a function of the applied magnetic fi eld. Temperature and angular dependences of the EPR spectra of the samples in the 3–300 K temperature range were analyzed applying both Lorentzian– –Gauss approximation for diluted medium and Dyson for dense magnetic medium. EPR-NMR program was done to fi nd local symmetry and spin Hamiltonian parameters of erbium ions.

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Spectroscopic studies of Er-doped Si-rich silicon oxide/SiO2 multilayers

Gourbilleau F., Dufour C., Madelon R., Rizk R.

Optica Applicata

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2007

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Vol. 37, nr 1-2

21-30

EN

The effects of Si nanocluster (Si-nc) size and of the distance between Si-nc and Er ion on the photoluminescence of the Er3+ ions have been investigated by means of appropriate multilayer configurations fabricated by reactive magnetron sputtering. On the one hand, the effect of Si-nc size is studied in Er-Si-rich SiO2/SiO2 multilayers. The coupling between Si-nc and Er3+ ions is found to be less efficient when the Si-nc?s reach a size of 5 nm and attributed to a loss of the quantum confinement of carriers. On the other hand, the interaction distance between Si-nc and Er ions is determined through the photoluminescence properties of Si-rich SiO2/Er-SiO2 multilayers. The characteristic interaction distance Si-nc-Er is dependent on the nature of the sensitizers with 0.4 ą 0.1 nm for amorphous Si and 2.6 ą 0.4 nm for Si nanocrystals.

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Badania reakcji dehydratacji kompleksów prazeodymu(III), neodymu(III), europu(III), gadolinu(III), dysprozu(III) i erbu(III) z kwasem kwercetyno-5'-sulfonowym

Kopacz M., Nowak D.

Zeszyty Naukowe Politechniki Rzeszowskiej. Chemia

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1999

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z. 16 [173]

45-49

PL

Przeprowadzono syntezę oraz badania derywatograficzne kompleksów jonów Pr(III), Nd(III), Eu(III), Gd(III), Dy(III), Er(III) z kwasem kwercetyno-5'sulfonowym i wyznaczono ich energię aktywacji (Ea) reakcji dehydratacji. Stwierdzono, że kompleksy prazeodymu, neodymu, gadolinu i erbu mają większe wartości energii aktywacji niż kompleksy europu i dysprozu.

EN

Thermogravimetric analysis complexes of Pr(III), Nd(III), Eu(III), Gd(III), Dy(III) and Er(III) ions with quercetin-5'-sulfonic acid were carried out. Activation energy (Ea) reaction of dehydration was appointed. It was stated, that complexes of praseodymium, neodymium, gadolinium and erbium had higher values of activation energy than complexes of europium and dysprosium.