{
  "id": "1111.7008",
  "version": "v1",
  "published": "2011-11-29T22:34:04.000Z",
  "updated": "2011-11-29T22:34:04.000Z",
  "title": "Magnetic properties and spin dynamics of 3d-4f molecular complexes",
  "authors": [
    "P. Khuntia",
    "M. Mariani",
    "A. V. Mahajan",
    "A. Lascialfari",
    "F. Borsa",
    "T. D. Pasatoiu",
    "M. Andruh"
  ],
  "journal": "Phys. Rev. B 84, 184439 (2011)",
  "doi": "10.1103/PhysRevB.84.184439",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci"
  ],
  "abstract": "We present the magnetic properties of three recently synthesized binuclear molecular complexes [NiNd], [NiGd] and [ZnGd] investigated by dc magnetization and proton nuclear magnetic resonance (NMR) measurements. The high-temperature magnetic properties are related to the independent paramagnetic behavior of the two magnetic metal ions within the binuclear entities both in [NiNd] and [NiGd]. On lowering the temperature, the formation of a magnetic dimer, with a low-spin ground state due to antiferromagnetic interaction (J/kB = -25 K) between Ni2+ and Nd3+, is found in the case of [NiNd], while in [NiGd] a ferromagnetic interaction (J/kB = 3.31 K) between the magnetic ions leads to a high-spin (S = 9/2) ground state. The temperature dependence of the proton nuclear spin lattice relaxation rate 1/T1 in [NiNd] is driven by the fluctuation of the hyperfine field at the nuclear site due to relaxation of the magnetization. At high temperature the independent Ni2+ and Nd3+ spins fluctuate fast while at low temperature we observe a slowing down of the fluctuation of the total magnetization of the dimer because of the insurgence of antiferromagnetic spin correlations. The relaxation mechanism in [NiNd] at low temperature is interpreted by a single, temperature dependent, correlation frequency wc\\simT^3.5, which reflects the life time broadening of the exchange coupled spins via spin-phonon interaction. The proton NMR signal in [NiGd] could be detected just at room temperature, due to the shortening of relaxation times when T is decreased. The magnetic properties of [ZnGd] are the ones expected from a weakly interacting assembly of isolated moments except for anomalies in the susceptibility and NMR results below 15 K which currently cannot be explained.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-11-29T22:34:04.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "75.50.Xx",
      "75.50.Ee",
      "76.60.Es"
    ],
    "keywords": [
      "magnetic properties",
      "3d-4f molecular complexes",
      "spin dynamics",
      "temperature",
      "proton nuclear spin lattice relaxation"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review B",
      "year": 2011,
      "month": "Nov",
      "volume": 84,
      "number": 18,
      "pages": 184439
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2011PhRvB..84r4439K"
    }
  }
}