Spin reorientation phenomena in Er2-xRxFe14B (R = Gd, Th) – Mössbauer and calorimetric study

• Autorzy: Wojciechowska A. , Pędziwiatr A. , Bogacz B. , Wróbel S.
• Konferencja: Proceedings of the All-Polish Seminar on Mössbauer Spectroscopy OSSM'06, June 18-21, 2006, Koszęcin, Poland
• Języki publikacji: EN

Abstrakty

EN

The Er2 xGdxFe14B (x = 0.5, 1.0, 1.5) and Er2 xThxFe14B (x = 0.0, 0.5, 1.0, 1.5, 2.0) polycrystalline compounds have been investigated with 57Fe Mössbauer spectroscopy and differential scanning calorimetry (DSC). A comparison of results related to spin reorientation phenomena obtained for Gd- and Th-substituted compounds is presented in this paper. Spin reorientation phenomena (changes from planar to axial spin arrangements) have been studied extensively by a narrow step temperature scanning in the neighbourhood of the spin reorientation temperature, TSR. From the analysis of Mössbauer spectra, it was deduced that in the region of transition each subspectrum was split into two Zeeman sextets, which were characterised by different hyperfine magnetic fields and quadrupole splittings. A consistent way of fitting the spectra in the wide range of temperatures was proposed. The composition and temperature dependencies of hyperfine interaction parameters and subspectra contributions were derived from fits and the transition temperatures were determined for all the compounds studied. DSC studies proved that the spin reorientations were accompanied by thermal effects for all compositions of the Gd- and for x = 0.5 of the Th-series. Transformation enthalpy and TSR were determined from these studies and the two-stage character of transition was confirmed. Magnetic spin arrangement diagrams for R = Th and Gd series were constructed and compared using combined data obtained with both methods.

Słowa kluczowe

EN

Mössbauer effect; spin reorientation

• Wydawca: Institute of Nuclear Chemistry and Technology
• Czasopismo: Nukleonika
• Rocznik: 2007
• Tom: Vol. 52, supl. 1
• Strony: 77--79
• Opis fizyczny: Bibliogr. 8 poz., rys.

Twórcy

autor

Wojciechowska A.

autor

Pędziwiatr A.

autor

Bogacz B.

autor

Wróbel S.

• The Marian Smoluchowski Institute of Physics, Jagiellonian University, 4 Reymonta Str., 30-059 Kraków, Poland, Tel.: [phone], Fax: [phone],

Bibliografia

• 1. Bogacz BF (2000) On the approximation of the Mössbauer integrals. Mol Phys Rep 30:15−20
• 2. Buschow KHJ, Van Noort HM, De Mooij DB (1985)Magnetic and structural properties of Nd2Fe14B,Th2Fe14B, Nd2Co14B and related materials. J Less-Common Met 109:79−91
• 3. Givord G, Li HS, Perrier de la Bathie R (1984) Magnetic properties of Y2Fe14B and Nd2Fe14B single crystals. Solid State Commun 51:857−860
• 4. Herbst JF, Croat JJ, Pinkerton FE, Yelon WB (1984) Relationships between crystal structure and magnetic properties in Nd2Fe14B. Phys Rev B 29:4176−4178
• 5. Hirosawa S, Matsuura Y, Yamamoto H, Fujimura S, Sagawa M, Yamauchi H (1985) Magnetization and magnetic anisotropy of R2Fe14B measured on single crystals. J Appl Phys 59:873−879
• 6. Pędziwiatr AT, Bogacz BF, Wojciechowska A, Wróbel S (2005) Experimental studies of spin reorientations in Er2−xThxFe14B. J Phys-Condens Matter 17:6999−7007
• 7. Pędziwiatr AT, Bogacz BF, Wojciechowska A, Wróbel S (2005) Spin reorientation studies in Er2−xGdxFe14B.J Alloys Compd 396:54−58
• 8. Wielgosz R, Pędziwiatr AT, Bogacz BF, Wróbel S (2000)Spin reorientation in Er2Fe14B intermetallic compound. Mol Phys Rep 30:167−173