title: High temperature magnetic order in Zn1-x Mn x SnSb2+MnSb nanocomposite ferromagnetic semiconductors.
abstract: We present studies of structural, magnetic, and electrical properties of Zn1-x Mn x SnSb2+MnSb nanocomposite ferromagnetic semiconductors with the average Mn-content, [Formula: see text], changing from 0.027 up to 0.138. The magnetic force microscope imaging done at room temperature shows the presence of a strong signal coming from MnSb clusters. Magnetic properties show the paramagnet-ferromagnet transition with the Curie temperature, T C, equal to about 522 K and the cluster-glass behavior with the transition temperature, T CG, equal to about 465 K, both related to MnSb clusters. The magnetotransport studies show that all investigated samples are p-type semiconductors with high hole concentration, p, changing from 10(21) to 10(22) cm(-3). A large increase in the resistivity as a function of the magnetic field is observed at T  <  10 K and small magnetic fields, [Formula: see text] mT, for all the studied samples with a maximum amplitude of the magnetoresistance about 460% at T  =  1.4 K. The large increase in the resistivity is most probably caused by the appearance of the superconducting state in the samples at T  <  4.3 K.
authors.affiliation: Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland.
authors.forename: L
authors.initials: L
authors.lastname: Kilanski
authors.forename: M
authors.initials: M
authors.lastname: Górska
authors.forename: A
authors.initials: A
authors.lastname: Ślawska-Waniewska
authors.forename: S
authors.initials: S
authors.lastname: Lewińska
authors.forename: R
authors.initials: R
authors.lastname: Szymczak
authors.forename: E
authors.initials: E
authors.lastname: Dynowska
authors.forename: A
authors.initials: A
authors.lastname: Podgórni
authors.forename: W
authors.initials: W
authors.lastname: Dobrowolski
authors.forename: U
authors.initials: U
authors.lastname: Ralević
authors.forename: R
authors.initials: R
authors.lastname: Gajić
authors.forename: N
authors.initials: N
authors.lastname: Romčević
authors.forename: I V
authors.initials: IV
authors.lastname: Fedorchenko
authors.forename: S F
authors.initials: SF
authors.lastname: Marenkin