Interacting AF NPs

Magnetic behaviour of interacting antiferromagnetic nanoparticles.
 V Markovich, R Puzniak, Y Skourski, A Wisniewski, D Mogilyanski, G Jung and G Gorodetsky
J. Phys.: Condens. Matter 24, 266001 (2012)

Exchange bias in manganite NPs

Evidence of exchange bias effect and surface spin glass ordering in electron doped Sm0.09Ca0.91MnO3 nanomanganites.
S. K. Giri, A. Poddar, and T. K. Nath
J. Appl. Phys.112, 113903 (2012)

The schematic representation of the phenomenological model forbulk manganites and the corresponding nanograins, described in the text.

Exchange bias and training effects in manganite NPs

Some articles devoted to finite-size and exchaneg bias effects in manganite NPs:

Oscillatory exchange bias and training effects in nanocrystalline Pr0.5Ca0.5MnO3.
S. Narayana Jammalamadaka, S. S. Rao, S. V. Bhat, J. Vanacken, and V. V. Moshchalkov
AIP Advances 2, 012169 (2012)

(a) T variation of oscillatory exchange bias field (OEB) (b) Variation of M with FC (c) M-H loops resulted from
one step and two step field cooling process. Symmetric MH loops are evident after two step process (d) HEB and HC variation with FC. The red curve is the fit obtained from equation (1), scattered points are the experimental data.

Probing the existing magnetic phases in Pr0.5Ca0.5MnO3 (PCMO) nanowires and nanoparticles: magnetization and magneto-transport investigations.
S S Rao and S V Bhat
J. Phys. Condens. Matter 22, 116004 (2010) 

After cooling PCMO 20 in 2, 6 and 8 T, the field is isothermally changed to 4 T at 5 K and the magnetization is measured while warming (FA 2 T, FA 6 T, FA 8 T). The variation of magnetization with the temperature in zero-field cooling (4 and 6 T), field-cooled cooling and warming at 4 T is shown as ZFC 4 T, ZFC 6 T and FCCW 4 T (a). A similar protocol was followed as mentioned above in the case of PCMO 40 to measure the magnetization with temperature (b).

Surface spin glass and exchange bias effect in Sm0.5Ca0.5MnO3 manganites nano particles
S. K. Giri, A. Poddar, and T. K. Nath
AIP Advances 1, 032110 (2011)

The schematic representation of the phenomenological model for CO/AFM bulk manganites and the corresponding nanograins.

Unexpected EB in La manganite films

Exchange-bias effect at La0.75Sr0.25MnO3/LaNiO3 interfaces
J. C. Rojas Sánchez, B. Nelson-Cheeseman, M. Granada, E. Arenholz, and L. B. Steren
Phys. Rev. B 85, 094427 (2012)

(a) Ni L2,3 and (b) Mn L2,3 XAS and XMCD spectra for LSMO tLSMO/LNO 8nm/LSMO//STO trilayers with (dash) tLSMO = 2.2 nm, (dot) tLSMO = 4.2nmand(solid) tLSMO = 8.1 nmrespectively. (c)Ni and (d)Mn normalized XMCD asymmetry vs. magnetic field.

Magnetodielectricity in a Manganites

Near-Room-Temperature Colossal Magnetodielectricity and Multiglass Properties in Partially Disordered La2NiMnO6.
D. Choudhury, P. Mandal, R. Mathieu, A. Hazarika, S. Rajan, A. Sundaresan, U.V. Waghmare, R. Knut,O. Karis, P. Nordblad, and D. D. Sarma
Phys. Rev. Lett. 108, 127201 (2012)

See also:
Charge Hopping in Glassy Magnets.
Gavin Lawes
Physica 5, 35 (2012)

(a) FC ZFC DC magnetization data, with an applied magnetic field (H) of 20 Oe. (b) The imaginary parts of AC susceptibility, with H =4 Oe. (c) Same as in (b), but focusing on the low-temperature region. (d) ZFC data with and without an intermediate wait (TW) at 25 K for 6000 seconds, showing distinct memory effects at TW as illustrated in the inset with a difference plot.

Finite-size effects and charge ordering suppresion on manganite NPs

Particle-size effects on the suppression of charge ordering in Nd0.8Na0.2MnO3
B. Samantaray, S. K. Srivastava, and S. Ravi
J. Appl. Phys. 111, 013919 (2012)

The phase diagrams of Nd0.8Na0.2MnO3 for (a) D=700-nm, (b) D=250-nm, and (c) D=140-nm particle-size samples
obtained from magnetization measurements. Open and closed circles represent the threshold fields HC1 and HC2, respectively, and stars represent HS values.

Finite-size effects on manganite NPs

Nanometer Size Effect on Magnetic Properties of Sm0.8Ca0.2MnO3 Nanoparticles.
Vladimir Markovich, Ivan Fita, Andrzej Wisniewski, Roman Puzniak, Dmitrii Mogilyansky, Przemyslaw Iwanowski, Piotr Dluzewski, and Gad Gorodetsky
J. Phys. Chem. C 116, 435 (2012)

(a,b) Magnetic field dependences of magnetization of SCMO23 and SCMO100 samples at T = 10 K measured after FC. Insets show a low field part of hysteresis loops on the extended scale. (c) Size dependence of spontaneous magnetization M0 and magnetization MS in H = 15 kOe at T = 10 K. (d) Coercive field of SCMO samples as a function of the particle size. Solid line is linear fit to the expression HC = a + b/D.

Size effect on manganite NP

Nanometer Size Effect on Magnetic Properties of Sm0.8Ca0.2MnO3 Nanoparticles.
Vladimir Markovich, Ivan Fita, Andrzej Wisniewski, Roman Puzniak, Dmitrii Mogilyansky, Przemyslaw Iwanowski, Piotr Dluzewski, and Gad Gorodetsky
J. Phys. Chem. 116, 435 (2012)

(a-d) Temperature dependence of real component of ac susceptibility (χ0) measured during heating at different frequencies and magnetic ac field of 10 Oe for SCMO samples. Insets show the imaginary part (χ00) of ac susceptibility measured at different frequencies and magnetic ac field of 10 Oe.

Manganite NPs phase diagram

Magnetic phase diagram and critical behavior of electron-doped LaxCa1−xMnO3 (0 < x< 0.25) nanoparticles.
Yang Wang and Hong Jin Fan
Phys. Rev. B 83, 224409 (2011)

Magnetic phase diagrams of Bulk (up) and Nanoparticles (down)