[Date Index] [Thread Index] [Author Index]

Re: Brillouin function for a Ferromagnet

• To: mathgroup at smc.vnet.net
• Subject: [mg111175] Re: Brillouin function for a Ferromagnet
• From: George Woodrow III <georgevw3 at mac.com>
• Date: Fri, 23 Jul 2010 07:08:12 -0400 (EDT)

You also do not want to use underscores in your variable names. The underscore has a special reserved meaning, which is explained in the fine documentation. Basically, it indicates that the preceding symbol is the pattern to be matched.

george

On Jul 22, 2010, at 5:43 AM, Themis Matsoukas wrote:

> Your question is ambiguous:
> 
> 1. Are you using regular math notation, or Mathematica notation? It appears you are using both, which makes it difficult to decipher the meaning of (), [], B_J.
> 
> 2. Did you mean to say B_J[x]=... ?
> 
> 3. Is J a known constant, or an unknown to be obtained from the fit?
> 
> Themis
> 
>> First I have to apologize if this is too basic for
>> this forum... I have some temperature dependent
>> magnetization data from a FeNi-alloy. The measurement
>> was done from RT up to the Curie temperature T_c of
>> the alloy. I want to compare my data to a Brillouin
>> function with different angular momenta J. Basically
>> I have to solve
>> 
>> M/M_0=B_J[(T_c/T)(M/M_0)], 
>> with 
>> B_J=(2J+1/J)coth[(2J+1/2J)x]-(1/2J)coth[x/2J],
>> where 
>> M_0 is the saturation magnetization
>> 
>> How do I basically solve this and in parallel fit it
>> to my data? In principle I want to obtain M_0 and
>> T_c. My data consists of M(T).
>> 
>> Thank you for your interest and answers,
>> Frank
>> 
>