Magnetization zero-field-cooled

Fig. 18 Field cooled (FCM), zero field cooled (ZFCM) and remnant (REM) magnetization temperature dependencies of [Mn(Cp )2][Ni(dsit)2]. From [53]...

Figure 6.5 (a) The formation of ferritin-mediated self-assembly of FePt nanoparticles via electrostatic interactions, (b) magnetic dipole-dipole interaction of ferritins assembled with FePt nanoparticles, and (c) zero field cooling and field cooling results for the ferritin-FePt nanoparticle composite film and individual components. Reprinted with permission from Srivastava, Samanta, Jordan, et al. (2007). Copyright 2007 American Chemical Society. 

Figure 14 Critical current density vs applied magnetic field for zero field cooled case (virgin) and various field cooled values, H = SO, 100, 150, 200, 300, 400, 550, 1000 Oe. The enhancement peak value for the field cooled data vs magnetic field is shown in the inset. Ref. 48.

Figure 11 Magnetization relaxation versus log(time) at 10 K in fields applied normal to a 0.7 /un-thick T Ca BaoCujOjQ superconducting film (Tc is 108 K). The solid triangles show relaxation due to flux creep out of the film in zero applied field after cooling in a 10 kOe field and removal of the field. The open triangles represent flux creep into the film in a S00 Oe field applied following zero field cooling. The dashed lines show the fit to Eq. (13).

Ac-susceptibility measurements on (Ga,Mn)As with x = 0.042 have been performed in alternating B from 0.1-4 mT. In the temperature dependence of susceptibility, there is a sharp peak at about 48 K at 0.1 mT, which suggests a ferromagnetic phase transition. The temperature and magnetic field dependence is rather complicated and an increase of B involves additional peaks (the number of which up to 4), which may be due to domain formation and domain wall movement (Sadowski et al. 2000). There is also a report about ac-susceptibility measurements on (Ga,Mn)As with x = 0.07, which shows that there is no difference between the field-cooled and zero-field cooled ac-susceptibilities measured with B = 10 mT (Van Esch et al. 1997). 

Fig. 1. Temperature dependence of the dc magnetic susceptibility of LuNi2B2C and YNi2B2C in a magnetic field of 20 Oe. ZFC and FC means zero field cooling and field cooling, respectively (after Nagarajan et al. 1994).

The magnetization data for these polycrystalline samples prompted a closer look with an oxygen-stoichiometric series of single-crystal samples in the range 0.15 < x < 0.50 (Zhou et al., 2001a). The zero-field-cooled (ZFC) and field-cooled (FC) magnetization M(T) under applied fields of 10 Oe, 50 Oe, and 5 kOe as well as the reciprocal magnetization M l(T)... 

TABLE 9 Magnetic properties of the homologous R-B-C(N) compounds RB15 5CN, RB22C2N, and RB28.5C4 (R = Er, Ho). Tf is defined as the peak temperature of the zero field cooled (ZFC) susceptibility... 

The detailed magnetic behavior of Fe clusters has been studied for the films with Fe clusters embedded in Ag [34]. In UHV conditions, preformed Fe clusters with a mean diameter of 3 nm from a gas-aggregation source were deposited in conjunction with atomic Ag vapor. In such films clusters can come into direct contact and interact via exchange. Films containing Fe cluster volume fraction from < 1 % (isolated clusters) to 100% (pure clusters with no matrix) have been studied at temperatures ranging from 2 to 300 K by magnetometry and field-cooled (FC)/zero-field-cooled (ZFC) measurements. 

Understanding the magnetic properties of a collection of well-isolated clusters is of great interest for exploring FePt clusters as a media for EHDR beyond 1 Tera bit/in. Dilute FePt C cluster films were prepared by the multilayer method as described earlier. Thus Stoner-Wohlfarth-like behavior has been observed in a FePt C cluster film with FePt volume fraction of 5 %, [45], Figure 27 shows the zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves for as-deposited and annealed FePt C cluster film with 5 vol. % FePt. 

Due to the KV and kBT relationship in single-domain particles, magnetic properties of a self-assembled magnetic nanoparticle array are usually size and temperature dependent. A typical zero-field-cooled (ZFC) and field-cooled (FC) scans of the 11 nm Co nanoparticle assembly is shown in Fig. 11(A) [12], in which magnetization is measured as a function of temperature. 

Figure 5. Comparison of the magnetic susceptibility data of III at 100 Oe with I and II under (a) field-cooled (FC) and (b) zero-field-cooled (ZFC) conditions.

Figure 23. (a) Zero-field cooled, FC, and REM magnetization curves for (Cp2Mn)[Ni(dmit)2]. (b)... 

There are two aspects to perfect diamagnetism in superconductors. The first is magnetic field exclnsion if a material in the normal state is zero field cooled (ZFC), that is, cooled below Tc to the superconducting state withont any magnetic field present, and then it is placed in an external magnetic field, the field will be excluded from the superconductor. The second aspect is magnetic field expulsion. If the same material in its normal state is placed in a magnetic field, the field will penetrate and have almost the same value inside and outside because the permeability fx is so close to the free space value fXo. If this material is then field cooled (FC), that is, cooled below E in the presence of this applied field, the field will be expelled from the material this is the Meissner effect that was mentioned earlier. 

Figure 9.8 Plot of zero-field cooled (ZFC) and field-cooled (PC) magnetization of Dy[TCNE]3 (left) and Gd[TCNE]3 (right) measured in a 5 Oe applied field. The low-temperature region is displayed with the hifurcation point at 8.5 and 3.5 K [65]. (Reprinted with permission from J.W. Raehiger, and J.S. Miller, Magnetic ordering in the rare earth molecule-hased magnets, Ln(TCNE)3 (Ln = Gd, Dy TONE = tetracyanoethylene), Inorganic Chemistry, 41, 3308-3312, 2002. 2002 American Chemical Society.)...

FIG. 3 Temperature dependence of the magnetization of a K,Ceo crystalline sample. The direction of temperature sweep in the field-cooled (FC) and the zero-field-cooled (ZFC) curves Is indicated by the arrows. 

The upper critical field value //, 2 has been determined from magnetization curves A/(7) taken by zero-field cooling to well below 7,., applying various fields in the range of 0.2 to 5 T, and recording values by warming the sample to well above T,. Typical magnetization curves for different fields are shown in the inset of Fig. 3(b). 

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