Collapse of ferromagnetism in itinerant-electron system: A magnetic, transport properties, and high pressure study of (Hf,Ta)Fe2 compounds

Abstract

International audienc

Cross over between ferro and antiferromagnetic order in Fe itinerant electron magnetism: An experimental and theoretical study of the model (Hf,Ta)Fe 2 Laves phases

“…This has been clearly seen by magnetostriction studies [17] as well as by X-ray diffraction [2]. The critical influence of volume has also been reported recently from magnetization studies performed under high applied pressure [18]. Large volume effect has been observed not only on the ordering temperature, but also on the magnetic order type thus modifying the magnetic phase diagram [18].…”

“…The ferromagnetic to antiferromagnetic transition is accompanied with large volume change without change in the crystal symmetry [2,13,17,19]. The x = 0.175 compound is a typical material showing such magnetic phase transitions [18]. The magnetic phase diagram of this compound has been qualitatively explained on the basis of the spin fluctuations theory proposed by Moriya and Usami [21] in which the ferromagnetic and antiferromagnetic components of spin fluctuations modes coexist.…”

“…The magnetic phase diagram of this compound has been qualitatively explained on the basis of the spin fluctuations theory proposed by Moriya and Usami [21] in which the ferromagnetic and antiferromagnetic components of spin fluctuations modes coexist. In addition an unusual transition between two different Curie-Weiss behaviours has been revealed in the paramagnetic region [18]. The intrinsic magnetic properties of this family of materials continue to attract much interest.…”

“…Hf 1Àx Ta x Fe 2 compounds have attracted much attention due to their interesting magnetic properties [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], magnetocaloric properties [11,14,20] and their potential applications in giant magnetoresistance [12,13] and magnetostrictive transducers [19]. From their pioneering works, Nishihara and Yamaguchi have established the magnetic phase diagram of the Hf 1Àx Ta x Fe 2 system by means of magnetization and Mössbauer spectroscopy experiments [1][2][3][4].…”

“…Indeed TaFe 2 is a antiferromagnet with a low Néel temperature, T N = 30 K whereas the HfFe 2 presents, on the contrary, a ferromagnetic order up to Curie temperature as high as 600 K. A complete solid solution is possible upon substitution of Ta for Hf, thus enabling to explore continuously the physical properties of this pseudobinary system at the verge of the ferromagnetic to antiferromagnetic order. Several studies have been carried out on the basis of this system including magnetization measurements [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], magnetocaloric one [11,14,20], transport properties investigation [12,13,18].…”