# Multiple nearest-neighbor exchange model for the frustrated magnetic molecules {Mo72Fe30} and {Mo72Cr30}

Title | Multiple nearest-neighbor exchange model for the frustrated magnetic molecules {Mo72Fe30} and {Mo72Cr30} |

Publication Type | Journal Article |

Year of Publication | 2008 |

Authors | Schroder C, Prozorov R, Kogerler P, Vannette MD, Fang XK, Luban M, Matsuo A, Kindo K, Muller A, Todea AM |

Journal Title | Physical Review B |

Volume | 77 |

Pages | 224409 |

Date Published | Jun |

Type of Article | Article |

ISBN Number | 1098-0121 |

Accession Number | ISI:000257289300051 |

Keywords | field, state, superconductors |

Abstract | Our measurements of the differential susceptibility partial derivative M/partial derivative H of the frustrated magnetic molecules {Mo72Fe30} and {Mo72Cr30} reveal a pronounced dependence on magnetic field (H) and temperature (T) in the low H-low T regime, contrary to the predictions of the existing models. Excellent agreement with experiment is achieved upon formulating a nearest-neighbor classical Heisenberg model where the 60 nearest-neighbor exchange interactions in each molecule, rather than being identical as has been assumed heretofore, are described by a two-parameter rectangular probability distribution of values of the exchange constant. We suggest that the probability distribution provides a convenient phenomenological platform for summarizing the combined effects of multiple microscopic mechanisms that disrupt the idealized picture of a Heisenberg model based on a single value of the nearest-neighbor exchange constant. |

DOI | 10.1103/PhysRevB.77.224409 |

Alternate Journal | Phys. Rev. B |