1-s2.0-S0254058414006981-main

rti

a a, * a b c c

s SciencLaboratoire de Physique des Materiaux, Faculte des Sc

c I3N and Physics Department, University of Aveiro, 381

ynthesrahedralts reveduces and oct

17 October 2014Accepted 26 October 2014

2 2 5 3 4

x 0.05, conrmed by the Raman spectroscopy study.

interactions and the octahedral antiferromagnetic ones between Fe and Fe ions.. All rights reserved.

pounds (of general formula ABO3) because of their unique catalyticaction [1], colossal magnetoresistance effects [2,3], and gas-sensingproperties [4e13].

Many materials of technological and scientic interest havestructures which derive from, or are related to, the parent ABO3

s is the rare-eartha Ln1xCaxFeIII1xa2 occupying the

A-site and Fe occupies the B-site. The structural characteristics ofthese compounds can lead to a range of useful physical properties,such as mixed electric and ionic conductivity and ordered magne-tism at elevated temperatures.While at present, most of the studiesof the technological applications of the Ln1xCaxFeO3d family havebeen focused on their catalytic ability for carbon monoxide andmethane oxidation. Similar classes of perovskite-related oxidematerials, such as the rare-earth strontium cobaltates, have beeninvestigated for use as cathode materials for Solid Oxide Fuel Cells

* Corresponding author.

Contents lists availab

Materials Chemis

evi

Materials Chemistry and Physics 149-150 (2015) 467e472E-mail address: [email protected] (M. Bejar). 2014 Elsevier B.V

1. Introduction

There has been much interest in perovskite-structured com-

perovskite structure. One such class of materialcalcium ferrites with the general formulFeIVxO3d (Ln lanthanide ion), with Ln3 and CPowder diffraction eld of 0.05 T, showed the presence of a ferromagneticeparamagnetic transition. The magnetic studyexposed that the magnetization decreases rst for x 0.10 samples and then increases for the two othersamples. This behavior was related to the competition between the Fe3eFe3 tetrahedral ferromagnetic

3 2Available online 4 November 2014

Keywords:Magnetic materialsRaman spectroscopy and scatteringMossbauer effect

The tted Mossbauer spectra exposed, for x 0.00 sample, the presence of a one sextuplet, related tothe Fe3 ion in the tetrahedral site, and a doublet. However, for x > 0.00 samples, the t results showedthe apparition of other sextuplets related to the Fe3O4 phase. The percentage of this latest phase wasfound to increase and to reach a maximum for the x 0.10 sample and to decrease after for x 0.15 and0.20 samples.The variation of the magnetization (M) as a function of the temperature (T), under an applied magnetich i g h l i g h t s

La0.8Ca0.2xPbxFeO3 compounds were sMossbauer study: presence of Fe3 tet For x > 0 samples, the Mossbauer resu The substitution of Ca2 by Pb2 intro Competition between tetrahedral FM a

a r t i c l e i n f o

Article history:Received 16 May 2014Received in revised formhttp://dx.doi.org/10.1016/j.matchemphys.2014.10.0470254-0584/ 2014 Elsevier B.V. All rights reserved.es, B.P. 1171, 3000 Sfax, Universite de Sfax, Tunisiaiences et Techniques, BP 523, 23000 Beni-Mellal, Universite Sultan Moulay Slimane, Morocco0-193 Aveiro, Portugal

ized by the solegel method.l site and a doublet for x 0 sample.aled the presence of Fe3O4 phase.change on the magnetization.ahedral AFM interactions.

a b s t r a c t

The La0.8Ca0.2xPbxFeO3 (x 0.00, 0.05, 0.10, 0.15 and 0.20) compounds were prepared by the solegelmethod using the citric acid route. The structural study revealed that all samples crystallized in the Pnmaorthorhombic structure with the apparition of Ca Fe O and Fe O secondary phases for samples witha Laboratoire de Physique Appliquee, Faculte debA. Benali , M. Bejar , E. Dhahri , M. Sajieddine , M.P.F. Graa , M.A. ValenteMagnetic, Raman and Mossbauer propeperovskite oxides

journal homepage: www.elses of double-doping LaFeO3

le at ScienceDirect

try and Physics

er.com/locate/matchemphys

citrate acid (all analytically pure) powders were weighted.The phase purity, the homogeneity, lattice structure and cell

spectra related to the presence of Fe3O4 and Ca2Fe2O5 secondary

one doublet (d). Parameters derived from the calculated spectra

y anparameters of our compounds were checked by X-ray diffraction(XRD) analysis (Siemens D5000 X-ray diffractometer, with mono-chromator CueKa radiation (lCu 1.5406 )). The XRD data werealso used for rening the lattice parameters by means of Rietveldanalysis [25], by using the FULLPROOF program software.

Room temperature (RT) Raman spectroscopy was performedunder backscattering geometry, using a Jobin Yvon HR 800 systemand an excitation wavelength of 473 nm. For the RT absorptionexperiments, a Shimadzu UV 2100 spectrometer was used intransmission mode in a wavelength range from 200 to 900 nm. TheRaman spectra were recorded with a modular double gratingexcitation spectrouorimeter with a TRIAX 320 emission mono-chromator (Fluorolog-3, Horiba Scientic) coupled to an HR 980Hamamatsu photomultiplier, using a front face acquisition mode.As an excitation source a 450 W X arc lamp was used [26].

The transmission 57Fe Mossbauer spectra were collected atroom temperature using a constant acceleration spectrometer anda 25 mCi 57Co source in Rh matrix in a constant acceleration modeusing standard conguration of Mossbauer spectrometer (Weissel).The velocity scale was calibrated using an a-Fe foil. Estimated iso-mer shifts (IS) are given relative to this standard. The tting of thespectra was carried out with a set of Lorentzian lines, determinedby least squares tting programme NORMOS.

The magnetic measurements were made using a cryogen freeVibrating Sample Magnetometer (VSM) that allows measurementsas a function of temperature (between 200 and 750 K), with a(SOFC) [14], ceramic membranes for high temperature oxygenseparation [15,16] and magnetic sensors [17]. For signicant Ca-doping, charge balance is maintained by a combination of Fe4

and oxygen vacancies (d > 0) [18]. At low temperatures,Ln1xCaxFeO3d compounds are reported to undergo a ChargeDisproportionation (CD) transition, in which the Fe4 dispropor-tionate into Fe3 and Fe5 [19]. This CD transition is thought to berelated to the observation of glass behavior [5]. The mixed oxida-tion state of Fe ion of the B-site and oxygen-site vacancies are bothimportant structural characteristics of these materials, withoxygen-site vacancies being necessary for good oxygen conduc-tivity [2] and the magnetic behavior being dependent on the Fe3/Fe4 (and reportedly Fe5) distribution and ratio [18e20]. Based onwhat appear to be impure samples, some works suggest a Neeltemperature (TN) for samples with x 0.25 of 693 K [21]. Inter-polation of other results [18,19] suggests a lower TN forLa0.8Ca0.2FeO3d samples in the region of 500e550 K. This lowertemperature suggests, in a room temperature measurement (T/TN ~ 0.6), that a moment reduction of about 15e20 % should beobserved. The lowest moment on Fe4 has a small effect with theexistence of any canting of the antiferromagnetism resulting in aferromagnetic moment.

In this work, the lead doping effects on the structural, Raman,Mossbauer and magnetic properties of La0.8Ca0.2xPbxFeO3(x 0.00, 0.05, 0.10, 0.15 and 0.20) compounds are discussed.

2. Experimental details

The nanosize crystalline La0.8Ca0.2xPbxFeO3 (x 0.00, 0.05, 0.10,0.15 and 0.20) compounds [22] were synthesized by the solegelmethod [23,24]. This method was chosen because it is known togive a high degree of homogeneity and the particle size can becontrolled up to the nanosize level. Stoichiometric amounts oflanthanum nitrate, lead nitrate, calcium nitrate, ferric nitrate and

A. Benali et al. / Materials Chemistr468maximum value of magnetic eld of 10 T.and including the area in percent, hyperne eld (Hhyp), isomershift (IS), quadruple splitting (QS) and the average hyperne eld() are reported in Table 1. For all the spectra, we notice thepresence of the sub-spectrum S1 and the doublet d independentlyof the content of iron. As the isomer shift reects the s-electrondensity at the iron nucleus, which is very sensitive to the ironoxidation state and coordination number, the sub-spectrum S1with IS in the range 0.35e0.37 mms1 to Fe3 ions is attributed inthe tetrahedral site. The presence of the doublet indicates thepresence of a paramagnetic nature of some of iron in the samples.For x > 0.05 samples, and according to Table 1, the hyperne pa-rameters revealed the presence of the Fe3O4 phase (sub-spectra S2and S3). The apparition of the later phase is conrmed by the XRDresults. The determined isomer shift values are in good argumentwith those reported in the literature for LaFeO [32], SrFeO [33]phases, as proved by DRX study. On the other hand, we note theapparition of an additional mode located at about 830 cm1, whichis not observed in the spectra of pure La0.8Ca0.2FeO3. This mode ischaracteristic for adsorbed oxygen species on the surface ofLa0.8Ca0.2xPbxFeO3 (x > 0.0) nanoparticles [30].

In addition, modes located at about 150, 220 and 410 cm1 canbe associated to Fe3O4 phase (Fig. 3(b)) [31]. These results are ingood coincidence with the DRX study previously mentioned.

3.3. Mossbauer spectroscopy

A Mossbauer study was performed on La0.8Ca0.2xPbxFeO3samples at room temperature and the obtained spectra with theirtting are shown in Fig. 4. The Mossbauer spectra show wellresolved peaks with a shape which changes when the compositionof iron increases suggesting a modication in the local iron envi-ronment. It is clear, that the insertion of Pb2 ion does not signi-cantly affect the global form of theMossbauer spectra but leads to anarrowing of the sextuplet peaks. The spectra were calculated withthe superposition of three magnetic sub-spectra (S1, S2 and S3) and3. Results and discussion

3.1. X-ray diffraction

Phase identication and structural analysis were carried out bythe X-Ray Diffraction (XRD) techniquewith Cu-Ka radiation at roomtemperature. The data were analyzed by the Rietveld method usingthe FULLPROOF program [27]. Fig. 1 shows examples of therenement results of XRD patterns for x 0.00 and 0.10 samples. Infact, samples with x < 0.10 crystallized in the orthorhombic struc-ture with Pnma space group. However, for samples with x 0.10,beside the orthorhombic phase, spectra revealed other peaksascribed to the Ca2Fe2O5 and Fe3O4 secondary phases identiedwith X0 Pert High Score Plus program.

3.2. Raman spectroscopy

Fig. 2 shows the RT Raman spectra of La0.8Ca0.2xPbxFeO3(x 0.00, 0.05, 0.10, 0.15 and 0.20) compounds. Some peaks relatedto the La0.8Ca0.2xPbxFeO3 main phase can be noticed in all samples.The Raman bands, for x 0.00, observed at 145, 170, 255, 285, 400,430 and 640 cm1 are similar to those reported by M. Popa et al.[28] and Y. Wang et al. [29] specic of the LaFeO3 oxide (Fig. 3(a)).However, with the increase of Pb-content (x s 0.0), other bandsappeared and their intensities increased with increasing lead-content. This can conrm the apparition of additional peaks in DRX

d Physics 149-150 (2015) 467e4723 2.5and LaMn0.5Fe0.5O3 [34] compounds.

A. Benali et al. / Materials Chemistry anFrom Table 1, we can note an increase of Fe3 ions in thetetrahedral site when increasing the lead-content. Also, thepercentage of the Fe3O4 phase increases and reaches a maximumfor the x 0.10 sample and decreases for x 0.15 and 0.20samples.

Fig. 1. Observed (circle), calculated (continuous line) and difference patterns (at the bottomvertical tick indicates the allowed reections.d Physics 149-150 (2015) 467e472 4693.4. Magnetic characterization

The temperature (T) dependence of the magnetization (M) forLa0.8Ca0.2xPbxFeO3 (x 0.00, 0.05, 0.10, 0.15 and 0.20) compoundsis displayed in Fig. 5 measured at two different applied magneticelds m0H 0.05 and 2 T. All samples underwent a

) of X-ray diffraction data for La0.8Ca0.2xPbxFeO3 (x 0.00 and 0.10) compounds. The

0 200 400 600 800 1000

x = 0.10

x = 0.15

x = 0.20

x = 0.20

x = 0.15

x = 0.10

x = 0.05

x = 0.00

-12 -8 -4 0 4 8 12Velocity (mm/s)

Fig. 4. Room temperature spectra of La0.8Ca0.2xPbxFeO3 (x 0.00e0.20) samplestted with three sextets and one doublet.

A. Benali et al. / Materials Chemistry and Physics 149-150 (2015) 467e472470x = 0.00

x = 0.05ferromagneticeparamagnetic transition phase at TC temperature,dened as the temperature at which the dM/dT-T curves reached aminimum (Fig. 6). For all samples, the TC value was approximatelyconstant and about 670 K.

As shown in Fig. 5, the magnetization (M) decreased rst forsamples with x 0.10 and then increased for compounds withx > 0.10. As known, Fe ion presents 3d6 4s2 valence electrons. Inthe case of low spin state of Fe2 ions, all 3d6 ions are compensated([Y[Y[Y, S 0) and they do not contribute to the total magneticmoment of oxide. In Fe3 doped samples, 3d5 electrons in the lowspin state can participate in a ferromagnetic ordering ([Y[Y[,S 1/2). To explain the behavior of the magnetic curves for x 0.00

0 200 400 600 800 1000Raman shift (cm-1)

Fig. 2. Raman scattering of La0.8Ca0.2xPbxFeO3 (x 0.00e0.20) compounds.

Fig. 3. Raman scattering of the magnetite Fe3O4 phase [28].sample, the magnetization was due to the low ferromagnetic in-teractions between the Fe3 ions in the tetrahedral site. Based onthis, an enhancement of the magnetization was expected whenincreasing the Pb-content given that the percentage of the Fe3 ionsin the tetrahedral site increases as previously mentioned in theMossbauer part. However, themagnetization decreased for x 0.05and 0.10 samples. This contradiction can be correlated to theapparition of the 2 and 3 iron valence, related the octahedral siteof Fe3O4 phase as mentioned previously in the Mossbauer part. Theapparition of the two valence state led to the introduction of an-tiferromagnetic interactions between these Fe3 and Fe2 octahe-dral site ions. In addition, H.D. Zhou et al. [35] proved that the Fe3/Fe2 redox couple is removed from the Fe4/Fe3 redox couple by alarge intra-atomic interaction Ueff U De. So, it can be assumedthat there is a competition between the Fe3eFe3 tetrahedralferromagnetic interactions and the octahedral antiferromagneticones. Going deeper, T. Maitra et al. [36] conrmed that the presenceof Fe2makes the FM phase less stable compared to the tetrahedralcase. The antiferromagnetic phase, therefore, stabilizes and becomemore predominant.Table 1Fitted Mossbauer parameters of La0.8Ca0.2xPbxFeO3 (x 0.00e0.20) compounds at300 K.

Samples Sub-spectrum Area (%) Hhyp (kOe) IS(mm/s)

QS(mm/s)

(kOe)

x 0.00 S1 22.2 492.8 0.36 // 428.7S2 20 468.8 0.35 //S3 54 418.0 0.32 //d 3.8 // 0.38 2.32

x 0.05 S1 33.7 503.0 0.36 // 452.8S2 20.5 484.1 0.31 //S3 42.1 437.2 0.30 //d 3.7 // 0.43 2.42

x 0.10 S1 34.8 512.3 0.37 // 486.7S2 13.5 463.0 0.67 //S3 50 492 0.29 //d 1.7 // 0.36 2.82

x 0.15 S1 62.7 516.5 0.35 // 478.1S2 5.7 463.0 0.67 //S3 26 492.0 0.29 //d 5.5 // 0.36 2.82

x 0.20 S1 85 523.8 0.35 // 485.4S2 2.3 463.0 0.67 //S3 6 492.0 0.29 //d 5.4 // 0.36 2.82

This competition leads to the reduction of the magnetization ascan be seen for samples with x 0.05 and 0.10. Note that, from theMossbauer study, it is deduced that the percentage of the Fe3O4phase reaches a maximum for this sample, which can explain thelower value of the magnetization for x 0.10 sample. Whencontinuing to increase the Pb-content, the Fe3O4 phase percentagedecreases, leading as a result to the decrease of the antiferromag-netic interactions and simultaneously there is an increase of theferromagnetic interactions between the tetrahedral Fe3. All thiscan explain the enhancement of the magnetization for x 0.15 and0.20 samples. For these two samples, the ferromagnetic in-teractions become very strong and the antiferromagnetic onesbecome very poor, which explains the spectacular magnetizationimprovement of the magnetization for x 0.20 sample.

Fig. 7 shows the applied magnetic eld (m0H) dependence of themagnetization (M) at two different temperatures of 5 and 300 K.The M (m0H) curves reveal that for m0H > 0.5 T, the magnetizationincreases linearly with the increase of the lead-content, which in-dicates the suppression of the antiferromagnetic componentobserved at low applied magnetic eld. However, the absence ofthe saturation of the magnetization until an applied magnetic eldof 10 T is noticeable. This signies that the suppression of the an-tiferromagnetic interactions is only partial.

4. Conclusion

This work investigated the effect of the insertion of the Pb ion onthe structural Raman, Mossbauer and magnetic properties ofLa0.8Ca0.2xPbxFeO3 (x 0.00, 0.05, 0.10, 0.15 and 0.20) compounds

200 300 400 500 600 7000

1

2

x = 0.00x = 0.05x = 0.10x = 0.15x = 0.20

Mag

netiz

atio

n (e

mu/

g)

T(K)

0H = 0.05 T

200 300 400 500 600 7000

2

4

6

8

Mag

netiz

atio

n (e

mu/

g)

0H = 2 T

T(K)

x = 0.00 x = 0.05 x = 0.10 x = 0.15x = 0.20

Fig. 5. Temperature dependence of magnetization of La0.8Ca0.2xPbxFeO3(x 0.00e0.20) compounds in magnetic eld m0H 0.05 and 2 T.

200 300 400 500 600 700 800

0.00

-0.01

0.9

0.6

0.0

Mag

netiz

atio

n (e

mu/

g)

T (K)

0.3

dM/dT (em

u/g.K)

TC = 669 K

x = 0.05

200 300 400 500 600 700 800T (K)

-0.02

-0.01

0.001.2

0.8

0.4

0.0 TC = 670 K

x = 0.15

Mag

netiz

atio

n (e

mu/

g) dM/dT (em

u/g.K)

Fig. 6. Temperature dependence of magnetization and the Curie temperature ofLa0.8Ca0.2xPbxFeO3 (x 0.05 and 0.15) compounds.

A. Benali et al. / Materials Chemistry and Physics 149-150 (2015) 467e472 471Fig. 7. Magnetic eld dependence (m0H) of magnetization (M) curves at two differenttemperatures of 5 and 300 K of La0.8Ca0.2xPbxFeO3 (x 0.00e0.20) compounds.

synthesized by the solegel method. The structural study revealedthat all samples crystallize in the Pnma orthorhombic phase withthe apparition of Ca2Fe2O5 and Fe3O4 secondary phases for sampleswith x 0.05. The presence of these latest phases was conrmed bythe Raman spectroscopic study.

The Mossbauer study revealed the presence of Fe3 tetrahedralsite and a doublet for x 0.00 sample. For x > 0.00 samples, theMossbauer patterns t results have shown the presence othersextuplets related to the Fe3O4 phase. From the t results, an in-crease of Fe3 ions in the tetrahedral site when increasing the Lead-content was induced and the percentage of the Fe3O4 phaseincreased and reached a maximum for the x 0.10 sample anddecreased for x 0.15 and 0.20 samples.

The variation of the magnetization (M) as a function of thetemperature (T), under an applied magnetic eld of 0.05 T, hasshown the presence of a ferromagneticeparamagnetic transition,occurring at the Curie temperature (TC), for all samples, which doesnot change signicantly with the lead-content. However, the sub-stitution of calcium by lead introduces a change on the magnitudeof the magnetization curves. This behavior was related to thecompeting mechanisms between the Fe3- Fe3 tetrahedral ferro-magnetic interactions and the octahedral antiferromagnetic onesbetween Fe3 and Fe2 ions.

Acknowledgment

[4] C.M. Chiu, J.F. Hu, C.J. Ji, Y.H. Chang, Thin Solid Films 342 (1999) 15e19.[5] Z.Y. Peng, X. Li, M.Y. Zhao, H. Cai, S.Q. Zhao, G.D. Hu, Thin Solid Films 286

(1996) 270e273.[6] C.M. Chiu, Y.H. Chang, Mater. Sci. Eng. A 266 (1999) 93e98.[7] C.M. Chiu, Y.H. Chang, Sens. Actuat. B 54 (1999) 236e242.[8] N.N. Toan, S. Saukko, V. Lantto, Sens. Actuat. B 327 (2003) 279e282.[9] L.B. Kong, Y.S. Shen, Sens. Actuat. B 54 (1996) 217e221.[10] Y.D. Wang, J.B. Chen, X.H. Wu, Mater. Lett. 49 (2001) 361e364.[11] M. Tomoda, S. Okano, Y. Itagaki, H. Aono, Y. Sadaoka, Sens. Actuat. B 97 (2004)

190e197.[12] D. Mantzavinos, A. Hartley, I.S. Metcalfe, M. Sahibzada, Solid State Ionics 134

(2000) 103e109.[13] M.J. Akhtar, Z.N. Akhtar, J.P. Dragun, C.R.A. Catlow, Solid State Ionics 104

(1997) 147e158.[14] S.J. Skinner, J. Inorg. Mater. 3 (2001) 113e121.[15] V.V. Kharton, A.V. Kovalevsky, A.A. Yaremchenko, F.M. Figueiredo,

E.M. Naumovich, A.L. Shaulo, F.M.B. Marques, J. Membr. Sci. 195 (2002)277e287.

[16] V.V. Kharton, A.A. Yaremchenko, A.V. Kovalevsky, A. Viskup, E.M. Naumovich,P.F. Kerko, J. Membr. Sci. 163 (1999) 307e317.

[17] L.L. Barcells, R. Enrich, A. Callega, J. Fontcuberta, X. Obradors, J. Appl. Phys. 81(1997) 4298e4300.

[18] Y.Q. Liang, N.L. Di, Z.H. Cheng, Phys. Rev. B 72 (2005) 134416.[19] J. Li, Hyperne Interact. 69 (1991) 573e576.[20] Y.Q. Liang, N.L. Di, Z.H. Cheng, J. Magn. Magn. Mater. 306 (2006) 35e39.[21] M.A. Ahmed, S.I. El-Dek, Mater. Sci. Eng. B 128 (2006) 30.[22] A. Benali, S. Azizi, M. Bejar, E. Dhahri, M.F.P. Graa, Ceram. Int. 40 (2014)

14367e14373.[23] M.P.F. Graa, C. Nico, M. Peres, M.A. Valente, T. Monteiro, J. Nanosci. Nano-

technol. 12 (2012) 1e7.[24] M.P.F. Graa, P.R. Prezas, M.M. Costa, M.A. Valente, J. Sol Gel Sci. Technol. 64

(2012) 78e85.[25] R.A. Young, The Rietveld Method, Oxford University Press, New York, 1993.[26] C. Nico, R. Fernandes, M.P.F. Graa, M. Elisa, B.A. Sava, R.C.C. Monteiro, L. Rino,

A. Benali et al. / Materials Chemistry and Physics 149-150 (2015) 467e472472This work, within the frame work of collaboration, is supportedby the Tunisian Ministry of Higher Education and ScienticResearch and the Portuguese Ministry of Higher Education andScientic Research (Portuguese Agency for Science and TechnologyFCT) Project TP/46/2012.

References

[1] L. Lisi, G. Bagnasco, P. Ciambelli, S.D. Rossi, P. Russo, M. Turco, J. Solid StateChem. 146 (1999) 176e183.

[2] J.F. Hu, C.J. Ji, H.W. Qin, J. Chen, Y.M. Hao, Y.X. Li, J. Magn. Magn. Mater. 241(2002) 271e275.

[3] H.W. Qin, C.J. Ji, H.D. Niu, L.M. Zhu, J. Magn. Magn. Mater. 263 (2003) 249e252.T. Monteiro, J. Luminescence 145 (2014) 582e587.[27] H.M. Rietveld, J. Appl. Crystallogr. 2 (1969) 65.[28] M. Popa, J. Frantti, M. Kakihana, Solid State Ionics 154e155 (2002) 135e141.[29] Y. Wang, J. Zhu, L. Zhang, X. Yang, L. Lude, X. Wang, Mater. Lett. 60 (2006)

1767e1770.[30] Y.M. Choi, H. Abernathy, H.T. Chen, M.C. Lin, M. Liu, Chem. Phys. Chem. 7

(2006) 1957.[31] C. Guo, Y. Hu, H. Qian, J. Ning, S. Xu, Mater. Charact. 62 (2011) 148e151.[32] F.M.A. Da Costa, A.J.C. Dos Santos, Inorg. Chim. Acta 140 (1987) 105.[33] L. Fournes, Y. Potin, J.C. Grenier, G. Demazeau, M. Pouchard, Solid State

Commun. 62 (1987) 239.[34] K. De, R. Ray, R.N. Panda, S. Giri, H. Nakamura, T. Kohara, J. Magn. Magn. Mater.

288 (2005) 339.[35] H.D. Zhou, J.B. Goodenough, J. Solid State Chem. 178 (2005) 3679e3685.[36] T. Maitra, R. Valent, J. Phys. Condens. Matter 17 (2005) 7417e7431.

Magnetic, Raman and Mssbauer properties of double-doping LaFeO3 perovskite oxides1. Introduction2. Experimental details3. Results and discussion3.1. X-ray diffraction3.2. Raman spectroscopy3.3. Mssbauer spectroscopy3.4. Magnetic characterization

4. ConclusionAcknowledgmentReferences