Magnetoresistivity As A Probe To The Field-induced Change Of Magnetic Entropy In R Al2 Compounds (r=pr,nd,tb,dy,ho,er)

The heat capacity CP (T) of the ferromagnetic compounds R Al2 (R=Pr,Nd,Tb,Dy,Ho,Er) was measured at zero and applied magnetic field of 5 T in the temperature interval from 2 to 200 K. From these results are calculated the magnetic component of the entropy change, -Δ Smag (T) =S (0,T) -S (H,T). From resistivity measurements, ρ (H,T), from 2 to 300 K in the same compounds, we calculated the resistivity change due to the applied magnetic field, -Δ ρmag (T) = [ρmag (0,T) - ρmag (H,T)]. The results are compared and we observed a similar dependence between -Δ ρmag (T) and (T/ TC) m Δ Smag (T) with m=0 for T≥ TC and m=1 for T≤ TC. A simple model using a Hamiltonian considering molecular and crystalline electric fields, in a mean field approximation, is adopted for the calculus. Our results show that theory and experiment are in good agreement showing that the magnetoresistivity is a probe to the field-induced change of magnetic entropy in these compounds and can be extended to other materials. A model for the factor connecting both quantities, -Δ Smag (T) and -Δ ρmag (T), is developed. This factor contains mainly the effective exchange integral which is related to Fermi energy that in turn is related to the electron effective mass. © 2006 The American Physical Society.7413Ziman, M., (1972) Electrons and Phonons, , Oxford University Press, LondonPurwins, H.G., Leson, A., (1990) Adv. Phys., 39, p. 309. , ADPHAH 0001-8732 10.1080/00018739000101511Pecharsky, V.K., Gschneidner Jr., K.A., Pecharsky, A.O., Tishin, A.M., (2001) Phys. Rev. B, 64, p. 144406. , PRBMDO 0163-1829 10.1103/PhysRevB.64.144406Potter, H.H., (1932) Philos. Mag., Suppl., 13, p. 233. , ADPHAH 0001-8732Alexander, S., Helman, J.S., Balberg, I., (1976) Phys. Rev. B, 13, p. 304. , PLRBAQ 0556-2805 10.1103/PhysRevB.13.304Potter, H.H., (1931) Proc. R. Soc. London, Ser. a, 132, p. 560. , PRLAAZ 1364-5021Ravishankar, K., Sablik, M.J., Levy, P.M., Uffer, L.F., (1974) AIP Conf. Proc., 18, p. 923. , APCPCS 0094-243XVan Daal, H.J., Buschow, K.H.J., (1969) Solid State Commun., 7, p. 217. , SSCOA4 0038-1098Inoue, T., Sankar, S.G., Craig, R.S., Wallace, W.E., Gschneidner Jr., K.A., (1977) J. Phys. Chem. Solids, 38, p. 487. , JPCSAW 0022-3697Deenadas, C., Thompson, A.W., Craig, R.S., Wallace, W.E., (1971) J. Phys. Chem. Solids, 32, p. 1853. , JPCSAW 0022-3697Ibarra, M.R., Lee, E.W., Del Moral, A., Moze, O., (1985) Solid State Commun., 53, p. 183. , SSCOA4 0038-1098Ibarra, M.R., Moze, O., Algarabel, P.A., Arnaudas, J.I., Abell, J.S., Del Moral, A., (1988) J. Phys. C, 21, p. 2735. , JPSOAW 0022-3719Griffiths, R.B., (1969) Phys. Rev., 188, p. 942. , PHRVAO 0031-899X 10.1103/PhysRev.188.942Dekker, A.J., (1965) J. Appl. Phys., 36, p. 906. , JAPIAU 0021-8979 10.1063/1.1714260Von Ranke, P.J., Pecharsky, V.K., Gschneidner Jr., K.A., (1998) Phys. Rev. B, 58, p. 12110. , PRBMDO 0163-1829 10.1103/PhysRevB.58.12110Christen, M., (1980) Solid State Commun., 36, p. 571. , SSCOA4 0038-1098Sablik, M.J., Pureur, P., Creuzet, G., Fert, A., Levy, P.M., (1983) Phys. Rev. B, 28, p. 3890. , PRBMDO 0163-1829 10.1103/PhysRevB.28.3890Furrer, A., Purwins, H.G., (1977) Phys. Rev. B, 16, p. 2131. , PLRBAQ 0556-2805 10.1103/PhysRevB.16.2131Tsai, T.H., Sellmyer, D.J., (1979) Phys. Rev. B, 20, p. 4577. , PRBMDO 0163-1829 10.1103/PhysRevB.20.4577Milchberg, H.M., Freeman, R.R., Davey, S.C., More, R.M., (1988) Phys. Rev. Lett., 61, p. 2364. , PRLTAO 0031-9007 10.1103/PhysRevLett.61.2364Rawat, R., Das, I., (2001) J. Phys.: Condens. Matter, 13, p. 379. , JCOMEL 0953-8984 10.1088/0953-8984/13/19/104Das, I., Rawat, R., (2000) Solid State Commun., 115, p. 207. , SSCOA4 0038-1098Xiong, C.M., Sun, J.R., Chen, Y.F., Shen, B.G., Du, J., Li, Y.X., (2005) IEEE Trans. Magn., 41, p. 122. , IEMGAQ 0018-946

The Giant Anisotropic Magnetocaloric Effect In Dyal2

We report on calculations of the anisotropic magnetocaloric effect in DyAl2 using a model Hamiltonian including crystalline electrical field effects. The anisotropic effect is produced by the rotation of a constant magnetic field from the easy to a hard magnetic direction in the crystal and is enhanced by the first order nature of the field induced spin reorientation transition. The calculated results indicate that for a field with modulus of 2 T rotating from a hard to the easy direction, the isothermal magnetic entropy (Δ Siso) and adiabatic temperature (Δ Tad) changes present peak values higher than 60% the ones observed in the usual process, in which the field direction is kept constant and the modulus of the field is varied. © 2008 American Institute of Physics.1049Tishin, A.M., Spichkin, Y.I., (2003) The Magnetocaloric Effect and Its Applications, , 1st ed. (Institute of Physics, Bristol)Warburg, E., (1881) Ann. Phys. (N.Y.), 13, p. 141. , 0003-4916Brown, G.V., (1976) J. Appl. Phys., 47, p. 3673. , 0021-8979 10.1063/1.323176Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494. , 0031-9007 10.1103/PhysRevLett.78.4494Von Ranke, P.J., De Oliveira, N.A., Mello, C., Garcia, D.C., De Souza, V.A., Magnus, A., Carvalho, G., (2006) Phys. Rev. B, 74, p. 054425. , 0163-1829 10.1103/PhysRevB.74.054425Hill, T.W., Wallace, W.E., Craig, R.S., Inuone, T.J., (1973) Solid State Chem., 8, p. 364. , 10.1016/S0022-4596(73)80036-2De Oliveira, I.G., Garcia, D.C., Von Ranke, P.J., (2007) J. Appl. Phys., 102, p. 073907. , 0021-8979 10.1063/1.2783781Lima, A.L., Tsokol, A.O., Gschneidner Jr., K.A., Pecharky, V.K., Lograsso, T.A., Schlagel, D.L., (2005) Phys. Rev. B, 72, p. 024403. , 0163-1829 10.1103/PhysRevB.72.024403Von Ranke, P.J., De Oliveira, I.G., Guimarães, A.P., Da Silva, X.A., (2000) Phys. Rev. B, 61, p. 447. , 0163-1829 10.1103/PhysRevB.61.447Von Ranke, P.J., De Oliveira, N.A., Garcia, D.C., De Sousa, V.S.R., De Souza, V.A., Magnus, A., Carvalho, G., Reis, M.S., (2007) Phys. Rev. B, 75, p. 184420. , 0163-1829 10.1103/PhysRevB.75.184420Purwins, H.G., Leson, A., (1990) Adv. Phys., 39, p. 309. , 0001-8732 10.1080/00018739000101511Von Ranke, P.J., Pecharsky, V.K., Gschneidner Jr., K.A., (1998) Phys. Rev. B, 58, p. 1211

Experimental And Theoretical Analyses Of Pr Al2 And Nd Al2 Composite For Use As An Active Magnetic Regenerator

We report the theoretical and experimental investigations on the magnetocaloric effect in the Pr Al2 and Nd Al2 compounds and a composite of these compounds for use as an active magnetic regenerator. The theoretical calculations were performed considering the crystalline electrical field anisotropy and the magnetocaloric potentials were calculated in the three main crystallographic directions. The experimental data, obtained for the polycrystalline samples, are in good agreement with the theoretical results. Also, an optimum molar fraction of the Pr Al2 and Nd Al2 composite was determined theoretically and experimentally and discussed in the framework of the optimum regeneration Ericsson cycle. © 2005 American Institute of Physics.978Brown, G.V., (1976) J. Appl. Phys., 47, p. 3673Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494Tegus, O., Bruck, E., Buschow, K.H.J., De Boer, F.R., (2002) Nature (London), 415, p. 150Wada, H., Taniguchi, K., Tanabe, Y., (2002) Mater. Trans., JIM, 43, p. 73Wada, H., Tanabe, Y., (2001) Appl. Phys. Lett., 79, p. 3302Von Ranke, P.J., Nobrega, E.P., De Oliveira, I.G., Gomes, A.M., Sarthour, R.S., (2001) Phys. Rev. B, 63, p. 184406Von Ranke, P.J., De Oliveira, N.A., Tovar Costa, M.V., Caldas, A., De Oliveira, I.G., Nobrega, E.P., (2001) J. Magn. Magn. Mater., 226, p. 990Von Ranke, P.J., Pecharsky, V.K., Gschneidner Jr., K.A., (1998) Phys. Rev. B, 58, p. 12110Von Ranke, P.J., De Oliveira, I.G., Guimarães, A.P., Da Silva, X.A., (2000) Phys. Rev. B, 61, p. 447Williams, H.J., Wernick, J.H., Nesbit, E.A., Sherwood, R.C., (1962) J. Phys. Soc. Jpn., 17, p. 91Swift, W.M., Wallace, W.E., (1968) J. Phys. Chem. Solids, 29, p. 2053Mader, K.H., Segal, E., Wallace, W.E., (1969) J. Phys. Chem. Solids, 30, p. 1Nereson, N., Olsen, C., Arnold, G., (1968) J. Appl. Phys., 39, p. 4605Nereson, N., Olsen, C., Arnold, G., (1966) J. Appl. Phys., 37, p. 4575Rossignol, M.F., (1980), University of GrenoblePurwins, H.G., Leson, A., (1990) Adv. Phys., 39, p. 309Lima, A.L., Oliveira, I.S., Gomes, A.M., Von Ranke, P.J., (2002) Phys. Rev. B, 65, p. 172411Hashimoto, T., Kuzuhara, T., Sahashi, M., Inomata, K., Tomokiyo, A., Yayama, H., (1991) J. Appl. Phys., 70, p. 1911Yan, Z., Chen, J., (1992) J. Appl. Phys., 72, p. 1Smaïli, A., Chahine, R., (1996) Adv. Cryog. Eng., 42, p. 445Dai, W., (1992) J. Appl. Phys., 71, p. 527

A Comparative Study Of The Magnetocaloric Effect In Rni2 (r=nd,gd,tb) Intermetallic Compounds

Conventional and anisotropic magnetocaloric effects were studied in cubic rare earth RNi2 (R=Nd,Gd,Tb) ferromagnetic intermetallic compounds. These three compounds are representative of small, null, and large magnetocrystalline anisotropy in the series, respectively. Magnetic measurements were performed in polycrystalline samples in order to obtain the isothermal magnetocaloric data, which were confronted with theoretical results based on mean field calculations. For the R=Tb case, we explore the crystalline electrical-field anisotropy to predict the anisotropic magnetocaloric behavior due to the rotation of an applied magnetic field of constant intensity. Our results suggest the possibility of using both conventional and anisotropic magnetic entropy changes to extend the range of temperatures for use in the magnetocaloric effect. © 2009 American Institute of Physics.1051Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494. , 0031-9007 10.1103/PhysRevLett.78.4494Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Appl. Phys. Lett., 70, p. 3299. , 0003-6951 10.1063/1.119206Von Ranke, P.J., De Oliveira, N.A., Mello, C., Garcia, D.C., De Souza, V.A., Carvalho, A.M.G., (2006) Phys. Rev. B, 74, p. 054425. , 0163-1829 10.1103/PhysRevB.74.054425De Oliveira, I.G., Garcia, D.C., Von Ranke, P.J., (2007) J. Appl. Phys., 102, p. 073907. , 0021-8979 10.1063/1.2783781Lima, A.L., Tsokol, A.O., Gschneidner Jr., K.A., Pecharsky, V.K., Lograsso, T.A., Schlagel, D.L., (2005) Phys. Rev. B, 72, p. 024403. , 0163-1829 10.1103/PhysRevB.72.024403Von Ranke, P.J., De Oliveira, N.A., Garcia, D.C., De Souza, V.S.R., De Souza, V.A., Carvalho, A.M.G., Gama, S., Reis, M.S., (2007) Phys. Rev. B, 75, p. 184420. , 0163-1829 10.1103/PhysRevB.75.184420Carvalho, A.M.G., Campoy, J.C.P., Coelho, A.A., Plaza, E.J.R., Gama, S., Von Ranke, P.J., (2005) J. Appl. Phys., 97, p. 083905. , 0021-8979 10.1063/1.1876575Plaza, E.J.R., De Sousa, V.S.R., Alho, B.P., Von Ranke, P.J., (unpublished)Von Ranke, P.J., De Oliveira, N.A., Plaza, E.J.R., De Souza, V.S.R., Alho, B., Carvalho, A.M.G., Gama, S., Reis, M.S., (2008) J. Appl. Phys., 104, p. 093906. , 0021-8979 10.1063/1.3009974Lindbaum, A., Gratz, E., Heathman, S., (2002) Phys. Rev. B, 65, p. 134114. , 0163-1829 10.1103/PhysRevB.65.134114Purwins, H.G., Leson, A., (1990) Adv. Phys., 39, p. 309. , 0001-8732 10.1080/00018739000101511Lea, K.R., Leask, M.J.M., Wolf, W.P., (1962) J. Phys. Chem. Solids, 23, p. 1381. , 0022-3697 10.1016/0022-3697(62)90192-0Stevens, K.W.H., (1952) Proc. Phys. Soc., London, Sect. A, 65, p. 209. , 0370-1298 10.1088/0370-1298/65/3/308Von Ranke, P.J., Pecharsky, V.K., Gschneidner Jr., K.A., (1998) Phys. Rev. B, 58, p. 12110. , 0163-1829 10.1103/PhysRevB.58.12110Von Ranke, P.J., Nóbrega, E.P., De Oliveira, I.G., Gomes, A.M., Sarthour, R.S., (2001) Phys. Rev. B, 63, p. 184406. , 0163-1829 10.1103/PhysRevB.63.18440

Magnetocaloric Effect: Overcoming The Magnetic Limit

We have studied anomalous peaks observed in magnetocaloric -ΔS(T) curves for systems that undergo first-order magnetostructural transitions. The origin of those peaks, which can exceed the conventional magnetic limit, R ln(2J+1), is discussed on thermodynamic bases by introducing an additional-exchange contribution (due to exchange constant variation arising from magnetostructural transition). We also applied a semiphenomenological model to include this additional-exchange contribution in Gd 5Si 2Ge 2- and MnAs-based systems, obtaining excellent results for the observed magnetocaloric effect. © 2008 Elsevier B.V. All rights reserved.3215446449Sahashi, M., Niu, H., Tohkai, Y., Inomata, K., Hashimoto, T., Kuzuhara, T., Tomokiyo, A., Yayama, H., (1987) IEEE Trans. Magn., MAG-23, p. 2853Wada, H., Tomekawa, S., Shiga, M., (1999) Cryogenics, 39, p. 915Fujita, A., Fujieda, S., Hasegawa, Y., Fukamichi, K., (2003) Phys. Rev. B, 67, p. 104416Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 494Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Appl. Phys. Lett., 70, p. 3299Tegus, O., Brück, E., Buschow, K.H.J., de Boer, F.R., (2002) Nature, 415, p. 150Wada, H., Taniguchi, K., Tanabe, Y., (2002) Mater. Trans., 43, p. 73Wada, H., Tanabe, Y., (2001) Appl. Phys. Lett., 79, p. 3302Pecharsky, V.K., Holm, A.P., Gschneidner Jr., K.A., Rink, R., (2003) Phys. Rev. Lett., 91, p. 197204Morellon, L., Arnold, Z., Magen, C., Ritter, C., Prokhnenko, O., Skorokhod, Y., Algarabel, P.A., Kamarad, J., (2004) Phys. Rev. Lett., 93, p. 137201Tishin, A.M., (1997) J. Alloys Compd., 250, p. 635von Ranke, P.J., Nóbrega, E.P., de Oliveira, I.G., Gomes, A.M., Sarthour, R.S., (2001) Phys. Rev. B, 63, p. 184406Gama, S., Coelho, A.A., de Campos, A., Carvalho, A.M.G., Gandra, F.C.G., von Ranke, P.J., de Oliveira, N.I., (2004) Phys. Rev. Lett., 93, p. 237202von Ranke, P.J., Gama, S., Coelho, A.A., de Campos, A., Carvalho, A.M.G., Gandra, F.C.G., de Oliveira, N.A., (2006) Phys. Rev. B, 73, p. 014415The magnetic entropy change can be obtained from experimental M(H, T) data through Maxwell's relation using either -ΔS=∫(-∂M/∂T)dH or equivalently -ΔS=(∫ΔMdH)/ΔTPecharsky, V.K., Gschneidner Jr., K.A., (1999) J. Appl. Phys., 86, p. 6315Amaral, J.S., Silva, M.J.O., Amaral, V.S., (2007) Appl. Phys. Lett., 91, p. 172503Liu, G.J., Sun, J.R., Shen, J., Gao, B., Zhang, H.W., Hu, F.X., Shen, B.G., (2007) Appl. Phys. Lett., 90, p. 032507Plaza, E.J.R., Campoy, J.C.P., (2007) Phys. Rev. B, 75, p. 174419Carvalho, A.M.G., Alves, C.S., de Campos, A., Coelho, A.A., Gama, S., Gandra, F.C.G., von Ranke, P.J., Oliveira, N.A., (2005) J. Appl. Phys., 97, pp. 10M320de Campos, A., Rocco, D.L., Carvalho, A.M.G., Caron, L., Coelho, A.A., Gama, S., da Silva, L.M., de Oliveira, N.A., (2006) Nat. Mater., 5, p. 82Bean, C.P., Rodbell, D.S., (1962) Phys. Rev., 126, p. 104Spichkin, Y.I., Tishin, A.M., (2005) J. Magn. Magn. Mater., 290-291, p. 700Paudyal, D., Pecharsky, V.K., Gschneidner Jr., K.A., Harmon, B.N., (2006) Phys. Rev. B, 73, p. 144406Chernenko, V.A., Wee, L., McCormick, P.G., Street, R., (1999) J. Appl. Phys., 85, p. 7833Mira, J., Rivadulla, F., Rivas, J., Fondado, A., Guidi, T., Caciuffo, R., Carsughi, F., Goodenough, J.B., (2003) Phys. Rev. Lett., 90, p. 097203Liu, G.J., Sun, J.R., Lin, J., Xie, Y.W., Zhao, T.Y., Zhang, H.W., Shen, B.G., (2006) Appl. Phys. Lett., 88, p. 21250

Study Of Heat Treatment On The Magnetocaloric Properties Of Gd 5(si 2ge 2) Alloy [estudo Do Tratamento Térmico Sobre As Propriedades Magnetocalóricas Da Liga Gd 5ge 2si 2]

The Gd 5(Ge 1-xSi x), x ≤ 0.5 based alloys are pontential candidates for magnetic refrigeration in the range ∼20 - ∼290 K. The use of these alloys in near room temperature applications offer considerable environmental benefits by eliminating ozone depleting, greenhouse, or hazardous gas/liquids refrigerants. Another advantage of magnetocaloric refrigerators is that the cooling power can be varied by scaling form milliwats to a few hundred watts as the cooling efficiency of magnetic refrigerators working with Gd reach values of 60% of the theoretical limit, comparated to only about 40% in the best gas-compression refrigerators. However, one of the majors obstacles for the use of that technology in large scale is the utilization of high pure Gd metal (99,99% wt.) to produce the Gd-Ge-Si alloys, as the impurity elements decrease the intensity of the magnetocaloric effect (EMC). In this work, we prove that annealling of the Gd 5Ge 2Si 2 can promote remarkable values for the EMC, comparated to that obtained for the alloy with high pure Gd. Also, the as cast alloy and the annealed alloy are not monophasic, but have at least two crystalline phases into its microstructure. Results for the optical and electronic microscopy and magnetization measurements are reported.21852193Zimm, C., Jastrab, A., Sternberg, A., Pecharsky, V., Gschneidner Jr., K., Osborne, M., Anderson, I., Description and Performance of a Near-Room Temperature Magnetic Refrigerator (1998) Advances in Cryogenic Engineering, 43, pp. 1759-1766Pecharsky, V.K., Gschneidner Jr., K.A., Giant Magnetocaloric Effect in Gd5(Si2Ge2) (1997) Phys. Rev. Lett., 78 (23), pp. 4494-4497Tishin, A.M., Magnetocaloric Effect in the Vicinity of Phase Transitions (1999) Cap. 4 of Handbook of Magnetic Materials, 12, p. 395. , Netherlands: Elsevier Science B. V., ed. K. H. J. BuschowTegus, O., Brück, E., Buschow, K.H.J., De Boer, F.R., Transition-Metal-Based Magnetic Refrigerants for Room-Temperature Applications (2002) Nature, 415, pp. 150-152A. O. PECHARSKY, K. A. GSCHNEIDNER, V. K. PECHARSKY AND C. E. SCHINDLER, comunicação pessoal. 2001 (Ames Laboratory - Iowa, U.S.A.)Gschneidner, K.A., Pecharsky, A.O., Pecharsky, V.K., Lograsso, T.A., Schlagel, D.L., (2000) Rare Earth and Actinides: Science, Technology and Applications IV, pp. 63-7

Magnetic And Magnetocaloric Properties Of Nd Monopnictides

The behavior of Nd monopnictides in the paramagnetic regime is studied with a Hamiltonian that includes crystalline field interactions, molecular and quadrupolar fields. Experimental results have been obtained from polycrystalline samples, and from analysis of low field curves we deduced molecular and quadrupolar field parameters. From the magnetization data, the NdP and NdAs magnetocaloric potentials -ΔSmag are well reproduced, and their experimental isofields are in agreement with the one calculated from the model and the proposed parameters. © 2004 Elsevier B.V. All rights reserved.272-276III23732374Von Ranke, P.J., Lima, A.L., Nobrega, E.P., Da Silva, X.A., Guimaracs, A.P., Oliveira, I.S., (2001) Phys. Rev. B, 63, p. 024422Schobinger-Papamantellos, P., Fischer, P., Vogt, O., Kaldis, E., (1973) J. Phys. C, 6, p. 725Furrer, A., Kjems, J., Vogt, O., (1972) J. Phys. C, 5, p. 2246Bak, P., Lindgard, P.A., (1973) J. Phys. C, 6, p. 3774Sato, M., Taylor, J.B., Calvert, L.D., (1967) J. Less-common Met., 12, p. 419Ono, S., Despault, J.G., Calvert, L.D., Taylor, J.B., (1970) J. Less-common Met., 22, p. 51Tsuchida, T., Nakamura, Y., Kancko, T., (1969) J. Phys. Soc. Jpn., 26, p. 284Hulliger, F., (1978) J. Magn. Magn. Mater., 8, p. 18

Magnetocaloric Effect And Transport Properties Of Gd5ge2(si1-xsnx)2 (x=0.23 And 0.40) Compounds

We report a study about the structural properties of polycrystalline samples of nominal composition Gd5Ge2(Si1-xSnx)2 (x=0.23, 0.40) that closely influence their physical behavior particularly related to electric resistivity and magnetocaloric (MCE) effect. The samples were characterized by X-ray diffraction (XRD) using the Rietveld refinement method, metallographic analyses, 119Sn Mössbauer spectroscopy, DC magnetization and electrical transport measurements. It was identified a Gd5Si2Ge2-monoclinic phase for x=0.23 and a Sm5Sn4-orthorhombic phase (type II) for x=0.40, both with two non-equivalent crystallographic sites for the Sn ions. We were able to infer on the role of tin on the magnetic and transport properties in these compounds. © 2007 Elsevier B.V. All rights reserved.3162 SPEC. ISS.368371Campoy, J.C.P., Plaza, E.J.R., Carvalho, A.M.G., Coelho, A.A., Gama, S., von Ranke, P.J., (2004) J. Magn. Magn. Mater., 272, p. 2375Pecharsky, V.K., Gschneidner Jr., K.A., (1997) J. Alloys Compds., 260, p. 98Morellon, L., Blasco, J., Algarabel, P.A., Ibarra, M.R., (2000) Phys. Rev. B, 62, p. 1022Wang, H.B., Altounian, Z., Ryan, D.H., (2002) Phys. Rev. B, 66, p. 214413Greenwood, N.N., Perkins, P.G., Wall, D.H., (1967) Symp. Faraday Soc., 1, p. 51Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494Sousa, J.B., Braga, M.E., Correia, F.C., Carpinteiro, F., Morellon, L., Algarabel, P.A., Ibarra, M.R., (2003) Phys. Rev. B, 67, p. 134416Levin, E.M., (1999) Phys. Rev. B, 60, p. 7993Levin, E.M., (2001) Phys. Rev. B, 63, p. 064426Levin, E.M., (2000) J. Magn. Magn. Mater., 210, p. 18