Limits...
Magneto-structural coupling in [Formula: see text].

Khan A, Kaneko H, Suzuki H, Naher S, Ahsan MH, Islam MA, Basith MA, Alam HM, Saha DK - Springerplus (2015)

Bottom Line: Two interactions, the Jahn-Teller interaction and the spin-Peierls-like interaction are co-exist in [Formula: see text] system.From these measurements the crystal structures are determined.The full width at half maximum and integrated intensity give the fruitful information for magnetic elastic interactions.

View Article: PubMed Central - PubMed

Affiliation: Shahjalal University of Science and Technology, Sylhet, 3114 Bangladesh.

ABSTRACT
[Formula: see text] compound is well Known to show the frustration of the spin structure. At 12 K, [Formula: see text] distorts to break symmetry of the degenerated frustrated spin states by the spin-Peierls-like phase transition, accompanying with the antiferromagnetic ordering. On the other hand, [Formula: see text] undergoes a Jahn-Teller phase transition at a temperature of 310 K, differing from the low temperature ferrimagnetic transition temperature [Formula: see text] of about 60 K. It is also reported that [Formula: see text] shows another magnetic phase transition at about 30 K. These two phase transitions accompanying with the lattice change can be understood by the magneto-elastic interactions. Two interactions, the Jahn-Teller interaction and the spin-Peierls-like interaction are co-exist in [Formula: see text] system. In this report the [Formula: see text] compounds with x = 0.8, 0.6 and 1 are investigated by the X-ray diffraction measurements. From these measurements the crystal structures are determined. The full width at half maximum and integrated intensity give the fruitful information for magnetic elastic interactions.

No MeSH data available.


Related in: MedlinePlus

Profile of () scans of (440) Bragg reflection of
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4556724&req=5

Fig4: Profile of () scans of (440) Bragg reflection of

Mentions: As discussed in the previous section, three phase transitions in are almost confirmed, though the third phase transition at about 30 K is still not well understood. With doping the nonmagnetic ion in place of the magnetic ion in the parent compound , these three phase transition temperatures can be expected to be lower temperatures. To investigate the crystal structure of the compound whole profiles of reflection peaks were measured at several temperatures 300, 80, 70, 60, 50, 30 and 15 K and refined by the Rietveld method. Structural parameters obtained by “RIETAN-2000” at 300, 80, 70, 60, 50, 30 and 15 K are listed in Tables 2, 3 and 4 respectively. At room temperatures, the prepared spinel compounds are rather homogeneous compound in the space group with lattice parameter and the refinement precision is given by the value of S = 1.2468. The overall quality of the fitting is fairly good. Profiles of scans of (440) Bragg reflection at 200 K , 150 K and 30 K are shown in Fig. 4. These profiles contain in the right shoulder of the peaks. At 150 K the profile of (440) already split into two peaks. This phase transition undergoes by JT interaction and also spin-Peierls-like interaction and as shown in Table 2, the symmetry of the crystal lowers from to Fddd.


Magneto-structural coupling in [Formula: see text].

Khan A, Kaneko H, Suzuki H, Naher S, Ahsan MH, Islam MA, Basith MA, Alam HM, Saha DK - Springerplus (2015)

Profile of () scans of (440) Bragg reflection of
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556724&req=5

Fig4: Profile of () scans of (440) Bragg reflection of
Mentions: As discussed in the previous section, three phase transitions in are almost confirmed, though the third phase transition at about 30 K is still not well understood. With doping the nonmagnetic ion in place of the magnetic ion in the parent compound , these three phase transition temperatures can be expected to be lower temperatures. To investigate the crystal structure of the compound whole profiles of reflection peaks were measured at several temperatures 300, 80, 70, 60, 50, 30 and 15 K and refined by the Rietveld method. Structural parameters obtained by “RIETAN-2000” at 300, 80, 70, 60, 50, 30 and 15 K are listed in Tables 2, 3 and 4 respectively. At room temperatures, the prepared spinel compounds are rather homogeneous compound in the space group with lattice parameter and the refinement precision is given by the value of S = 1.2468. The overall quality of the fitting is fairly good. Profiles of scans of (440) Bragg reflection at 200 K , 150 K and 30 K are shown in Fig. 4. These profiles contain in the right shoulder of the peaks. At 150 K the profile of (440) already split into two peaks. This phase transition undergoes by JT interaction and also spin-Peierls-like interaction and as shown in Table 2, the symmetry of the crystal lowers from to Fddd.

Bottom Line: Two interactions, the Jahn-Teller interaction and the spin-Peierls-like interaction are co-exist in [Formula: see text] system.From these measurements the crystal structures are determined.The full width at half maximum and integrated intensity give the fruitful information for magnetic elastic interactions.

View Article: PubMed Central - PubMed

Affiliation: Shahjalal University of Science and Technology, Sylhet, 3114 Bangladesh.

ABSTRACT
[Formula: see text] compound is well Known to show the frustration of the spin structure. At 12 K, [Formula: see text] distorts to break symmetry of the degenerated frustrated spin states by the spin-Peierls-like phase transition, accompanying with the antiferromagnetic ordering. On the other hand, [Formula: see text] undergoes a Jahn-Teller phase transition at a temperature of 310 K, differing from the low temperature ferrimagnetic transition temperature [Formula: see text] of about 60 K. It is also reported that [Formula: see text] shows another magnetic phase transition at about 30 K. These two phase transitions accompanying with the lattice change can be understood by the magneto-elastic interactions. Two interactions, the Jahn-Teller interaction and the spin-Peierls-like interaction are co-exist in [Formula: see text] system. In this report the [Formula: see text] compounds with x = 0.8, 0.6 and 1 are investigated by the X-ray diffraction measurements. From these measurements the crystal structures are determined. The full width at half maximum and integrated intensity give the fruitful information for magnetic elastic interactions.

No MeSH data available.


Related in: MedlinePlus